Author Topic: Vintage chip Programmer : " Micropross ROM 3000U "  (Read 18356 times)

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Offline pcprogrammer

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #25 on: November 01, 2022, 10:29:10 am »
Reverse engineering 6502 is peanuts 8)

Every chip used in the thing must have some datasheet somewhere on the web.

But yes you can have lots of fun with it.

Offline syau

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #26 on: November 01, 2022, 10:32:16 am »
Wonder if one of the DB9 port is digital CGA/EGA/VGA which is common in these days before move to 15 pin analog VGA.
« Last Edit: November 01, 2022, 10:49:06 am by syau »
 
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Offline alm

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #27 on: November 01, 2022, 12:57:05 pm »
I believe in the vintage computer community there's a lot of experience in dealing with legacy floppies and unusal formats. There are even emulators like Gotek and HxC that will take modern media and emulate a floppy drive. If someone had access to an original floppy, it would probably be possible to clone (to another floppy or to modern media) given the right equipment and knowledge.

I would see if there's any vintage computer using the same floppy format, and see what people have written about it. Of course this is probably useless without having access to an original floppy.

Offline VinceTopic starter

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #28 on: November 01, 2022, 02:24:06 pm »
OK, 14H30 here, spent all my time since I got up, working on this thing !

Did what I said last night, took the time to probe all 8 pins on that back plane connector, to look more closely at what might be video signals.

It all went well and I thinkj I can confirm it's indeed our much desired video output, and it's well and alive !

So as explained, no appropriate Dupont wires here, so I dug out and old floppy drive ribbon cable and sacrificed it. Works just fine. I was able to secure my scope probe and have both hands free to observe the signal at great length.. and take pics and even a video, going modern here ! :-DD

So here is what I could figure out :

Pin #1 = GND
Pin #2 = Slow Clock signal, about 21.5ms / 46.5Hz , short 1.04 ms pulses.
Pin #3 = Video data / signal
Pin #4 = +12V
Pin #5 = Fast Clock signal, about 65µs / 15kHz, short 8µs pulses.
Pin #6 = Video data / signal
Pin #7 = Video data / signal
Pin #8 = +5V



So we have 3 video signals. So that means the programmer, well its big brother the 5000D version, was meant to be connected potentially to fancy colour monitors.
Unsurprisingly, since the CRT controller is monochrome only, I witnessed that all 3 video signals showed identical content. I guess this makes it compatible with colour monitors.
So that's good, it means I don't need to search for an antique monochrome only vintage monitor. A colour one hence maybe of a more modern / easier to find, design, might be compatible. With some luck we might find out later that it's compatible with good old VGA, in which case I can just grab any of my old monitors here !  :D  But it's too early to be that optimistic just yet...

Clocks : I guess the slow one could be the vertical sync signal, telling the monitor when to start drawing a screen / frame ? 46.5Hz is about the kind of refresh rates we used to have on old monitors eh ? Sounds plausible.
Then the faster clock I guess is the horizontal sync signal ?

My time/frequency measurements are only approximate of course, just me trying to measure them as best I could on the scope, but maybe that's good enough to try to figure out what kind of old video standard it might correspond to ? VGA or not ? CGA ? Whatever.... anyone knows these things ?

Signal amplitude : I notice that the video signal is not TTL / 5V, despite the CRT chip being of course TTL levels. They get only to 4V.
I am thinking that it may be normal. Maybe the last 1V is used as headroom to make the text brighter than the normal text.

OK so now for the dessert : I scoped, and filmed, what the video signal is doing during the entire bot process.

I used two probes. First signal at the top, in small to preserve screen real estate, is Vertical Sync, for reference, so that we know where a frame starts and ends, so we can make sense of the contents of the video data, know where it starts where it ends.

The boot process / video lasts about 1min30sec so I am sure you will make the effort to watch it, hopefully....

Before you do watch it, let me explain :

- I set the time base to 5ms so that we can see two screens worth of data : one screen on the first half of the graticule, then another screen, and towards the end we see a little bit / beginning of the third screen.

- I gave up using the scope (my Philips Combiscope) in analog mode because it was unwatchable and signals hard to see. Switched to digital mode. The pulses look crap of course, but at least the screen is not blinking, the brightness is even between ground level and the pulses, and you can see easily the pulses. In short it looks horrible but it conveys the important message much better... so I went for that. Lesser of two evils.

OK so here is what is going on :

- First, you see no signal. Programmer is powered up.

- Then I power it up, and soon signals stabilize.

- We can see that the video content appears to start on the falling edge of the Vsync signal.
- We have data/content during the first third of the screen, then dead space for about half of the screen, then at the end we have some content again.
- This content remains unchanged during the entire boot process
- Then when the boot is complete (you can hear the floppy drive stops making noise), the content changes, with only a little bit of data at the very beginning and at the very end, and all dead space in between
- Now during the boot process, do you notice something interesting ? Look at the first packet of data. At the end of this packet, there is an area that literrally "blink", regularly, like clock work, during the entire boot process. It blinks at the same speed that a blinking cursor on a text screen would !  >:D


SO !

From all that, I think we can say that :

At power up, the programmer displays some content for the top third of the screen, maybe some splash / welcome screen, and below that a blinking cursor to indicate that booting is in progress. The at the very bottom of the screen, some content again, maybe a status bar or god knows what.

Once booting is complete, it clears the screen, cursor stops blinking, and we are left with only a bit of text at the top, maybe a command prompt, and a little bit of text at the bottom, maybe a status bar, menu bar detailing options, whatever.

How cool ! Just looking at my scope and living the boot process as if I had a monitor actually plugged in, trying to imagine what would be going on on the monitor !!  >:D


Oh I love this thing, so fun and exciting working on it !!  :D

OK so we are making good progress here aren't we ? We know we have a video output, that it's actually active even though not available to the user at the rear. That's fantastic news. And we now also have details about the signals being generated, and their timing and amplitude !

So now let's figure out what kind video standard that is, and let's plug some monitor !!!  :box:




« Last Edit: November 01, 2022, 08:20:48 pm by Vince »
 

Offline VinceTopic starter

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #29 on: November 01, 2022, 02:59:56 pm »
Hmm making progress !


I just Googled a bit about VGA.
Looks like it can work with just RGB Hsync and Vsync like we have here on this programmer, cool.

However it says that voltage levels for VGA is standardized to 0V for black and 0.7V max for white.

This means that our video output is not meant for VGA, since our voltage levels go up to 4V, with suspicions that it may go all the way to TTL / 5V for extra brightness.

However, since I have only VGA monitors here, no older standards, I am thinking I could maybe just lower the voltage with simple resistive dividers (or just a trimmer, might be better to fine tune/experiment...)  ?  Just for fun really, just to see if I can get a VGA monitor to display "something".... anything at all... no matter how scrambled or distorted, would be fun to see !!!  >:D

Will try that !!!  :popcorn:
 

Offline pcprogrammer

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #30 on: November 01, 2022, 03:15:26 pm »
Hi Vince,

good work. You found the video levels for VGA too, and a restive divider will work.

The video signal looks interesting and what came to my mind was some blinking cursor shown while booting.

Will be nice to see it on an actual monitor. :-+

Edit: The clicking noise on the video is that the floppy drive?
« Last Edit: November 01, 2022, 03:18:58 pm by pcprogrammer »
 

Offline VinceTopic starter

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #31 on: November 01, 2022, 03:25:28 pm »
Yes the noise in the video is the floppy drive working !
I enabled the audio in the video so you can hear it and "live" the boot process, and then match its disappearance with the change in contents of the video data.

« Last Edit: November 01, 2022, 03:45:08 pm by Vince »
 
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Offline pcprogrammer

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #32 on: November 01, 2022, 04:11:47 pm »
Hi Vince,

I forgot that in the old days we had monitors with TTL inputs, so the 4V level you are measuring is not to allow some headroom for brightness, it is just the outputs not reaching the rail.

For the VGA monitor the inputs are 75 ohms, so adding a resistor in series of 390 or 470 ohms will do. You can test it with only one of the signals, but means that what you see on screen will not be white, but the color of the input you are using.

Offline VinceTopic starter

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #33 on: November 01, 2022, 06:10:48 pm »
Thanks for that. Saw your comment just in time before I fired it up, so made that last minute change !  :-DD

Just powered it up... sadly the monitor doesn't detect a valid signal.

Took me over an hour to manage to connect the programmer to a freaking VGA cable, believe it or not !

So many things went wrong. everything. It's amazing how much can go wrong in such a simple "project" !  :wtf:
Interconnect and prototyping definitely is not as quick and easy as I would like it to be.
My "best" solution, given what I had to work with, is this fragile horrible mess.

Anyway it doesn't work, miracle don't happen so easily....

I will try to troubleshoot it but it's a pain. I think I might as well spend more time and a we bit of money, a few euros, to try to make something less convoluted/simpler, more compact, more tidy, more reliable....
Since I will be working on this programmer for months and years, I need a much more durable and reliable and less messy solution. Something I can just plug and play.
I will probably end up making a little board on Kicad and make a dedicated adapter.  Yeah, see, YET ANOTHER little sub-project inside the project..... inside the main project !  :-DD

Electronics is a fun hobby !  >:D



 

Offline VinceTopic starter

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #34 on: November 01, 2022, 07:46:50 pm »
OK, 1+ hour of troubleshooting later....

Found that the signals from the programmer were not making it to the breadboard...

... found out that my ugly FDD cable hack was not a good idea : the cable had already gone bad, pin #1 which carries ground, was not making it to the other end of the cable any more  ::)

So did something better, which I should have done from the get go.... used a female header strip, cut it to length / 8 ways, and soldered solid core wires (much easier to stick into the breadboard holes than the tinned super thin stranded wires of the FDD ribbon cable....) to it, which was surprisingly much easier and quicker than I thought it would be... why didn't I think of doing that in the first place rather hacking an FDD cable... brain fart I guess...
Added bonus : now that I know what signals / pins I need, I could solder only 4 wires to the female header, so much tidier than before. So  a great upgrade so to speak, see it's already improving !  ;D

Other issue I found... looks like I got the pinout wrong in my earlier post (corrected now...) ! I thought I had ground on pin #1 and #8... well I found out pin #8 actually puts out 5V !!!  :wtf:
I don't know...
So since I of course put the two "grounds" together, I was therefore shorting that 5V something to ground ! Does not help...

Anyway, I now have my signals making it to the breadboard properly, and I also scoped the video signal after the 390R resistor, and I do get about 0.7V so it's perfect  8)

So, was looking much better, so I hooked a monitor up !

Result : no signal detected !  :(

Tried another monitor.. still no signal detected, ARGH !!!  :(

Tried a third monitor, the last I have.... SIGNAL DETECTED, YES  !!!!  :box:
HOWEVER... no picture, because the monitor complains that the signal is "not optimal, I should use resolution XXX and refresh rate YYY instead ! "
FFS don't THINK stupid you, just freaking display what I am giving you !!!  :horse:

I thought OK maybe I got the Hsync and Vsync mixed up.... so I swapped them just to see. Result : fails to detect the signal.

So that means I got them right the first time and it's indeed detecting a signal.... it's just that it doesn't like the timing enough to bother trying to display that signal, bummer  >:(

I guess sub 50Hz refresh rates are so crap that the designers of the monitor thought no customer would ever be likely to be feeding such a signal !  I don't know.... can't blame them I guess.

That's the problem with LCD / modern monitors, their VGA input just can't be relied on ! It's OK to connect to a computer graphics card, or a more modern piece of TE like a digital scope with a VGA resolution, but that's about it. To ther defense I guess that precisely all they meant to achieve with this VGA port, and indeed one of my monitors calls it the " PC " input ! Says it all.

But for older / vintage stuff, you need an actual CRT monitor.. the real thing. Of course I had 3 of them up until recently but scrapped them all to make space. I knew I would regret it. It's always like that.  :palm:

I can try to use my computer's monitor, my last hope.... but not holding my breath.

I guess I will need to go get a cheap old but decent CRT monitor locally, like the ones I had. Will see what I can find within a few kms radius from home.

« Last Edit: November 01, 2022, 08:00:13 pm by Vince »
 

Offline VinceTopic starter

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #35 on: November 01, 2022, 08:02:44 pm »
OK, just tried my computer monitor (LCD too), fourth and last monitor I have here.
Deos the same as the previous monitor : does detect a signal but no picture because it does not like the timing. I says,in scary red background : " OUT OF RANGE ".

So it confirms the diagnosis from the other monitor then.

OK I will see if I can find a decent CRT monitor locally, and will get back to you !  >:D

 

Offline pcprogrammer

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #36 on: November 01, 2022, 08:13:50 pm »
Hi Vince,

it might be that the sync signals need to be inverted. And maybe they also need a resistor in series. Could not find the levels of them with a quick search.

https://xess.com/blog/vga-the-rest-of-the-story/

Edit: And you will probably need a monitor that can handle the ~15KHz. It is basically old TV standard so indeed a CRT based monitor would do. Otherwise some upscale device can probably be found. Adrian's Digital Basement uses one.

Regards,
Peter
« Last Edit: November 01, 2022, 08:18:38 pm by pcprogrammer »
 

Offline VinceTopic starter

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #37 on: November 01, 2022, 08:33:12 pm »
Upscale device ?! didn't know about these things, thanks will keep that in mind  :-+

Sync signal amplitude ? Yes I did think of looking that up because I wondered if tehy had to be 0.7V as well or not. They don't, they are considered digital signal so are meant to stay at TTL levels.

HOWEVER you were right about polarity ! I forgot to pay attention to that, and indeed they are logic NEGATIVE  not positive !  :scared:

Let me invert them and see how we are doing after that !!!   >:D

Well not sure I will embark into that this evening.. .it's already 21H30 am getting tired and the 4 day long week-end is now over, I must resume work tomorrow !  :(

So that might be rather for tomorrow evening after work.

I could invert the signals using a couple transistors but I think using a TTL logic chip will be more tidy and compact.

Stay tuned !  >:D
 
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Offline VinceTopic starter

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #38 on: November 01, 2022, 09:11:58 pm »
Done.

Was quick in the end.

PIcked a 74LS04 in my stock, added that to the breadboard.

Need a 5V supply for it... I have one handy !

Pin #8 that I thought was ground whch turned out to be +5V instead !  :-DD

Well I now I am using it for what it actually is ! 8)

Scoped my HV Sync signals, they are inverted properly and are clean.

Monitor still complains as before, but well, it needed inverting no matter what !

OK so now the hunt for a CRT begins...

 

Offline VinceTopic starter

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #39 on: November 01, 2022, 09:50:02 pm »
Had a look for local ads.... many hundreds of screens within 20kms around me, incredible... but only 2 or 3 CRT monitors ! :scared:

Found this one real close to me https://www.leboncoin.fr/informatique/2020623493.htm 

A few minutes drive away. 10 Euros (I offered 6 Euros via the website), says it works. A DELL, looks decent and although ad says nothing about model or screen size, it does not look too big which is good as I have zero space, my back is fragile and since we need it for very low resolution pictures, 14" would be plenty enough, so anything above that is already questionable... but you get what you can find, and this one looks overall OK.

Sent the guy a message, asking if the thing is still available because... well the ad is a year and 3 months old !  :scared:

 

Offline Zoli

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #40 on: November 02, 2022, 05:23:29 am »
Had a look for local ads.... many hundreds of screens within 20kms around me, incredible... but only 2 or 3 CRT monitors ! :scared:

Found this one real close to me https://www.leboncoin.fr/informatique/2020623493.htm 

A few minutes drive away. 10 Euros (I offered 6 Euros via the website), says it works. A DELL, looks decent and although ad says nothing about model or screen size, it does not look too big which is good as I have zero space, my back is fragile and since we need it for very low resolution pictures, 14" would be plenty enough, so anything above that is already questionable... but you get what you can find, and this one looks overall OK.

Sent the guy a message, asking if the thing is still available because... well the ad is a year and 3 months old !  :scared:
VGA monitors start at 31.5kHz&up on horizontal frequency; what you need here is a CGA/Hercules/EGA monitor, since those are capable of 15-16kHz horizontal frequency; or an up-scaler which can handle the signal.

Edit: another option would be to generate composite video from the available signals.
« Last Edit: November 02, 2022, 01:23:41 pm by Zoli »
 
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Offline pcprogrammer

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #41 on: November 02, 2022, 05:48:51 am »
Like Zoli wrote, I don't think that monitor will do.

Here is what Adrian from his Digital Basement is using. https://www.retrotink.com/ It is not cheap but for playing with old computer hardware it saves a lot on space.

This is another one he did a video about. https://texelec.com/product/rgbtohdmi-ttl/




Edit: Found something less fancy on Aliexpress https://nl.aliexpress.com/item/4000516564335.html
« Last Edit: November 02, 2022, 05:59:48 am by pcprogrammer »
 

Offline VinceTopic starter

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #42 on: November 02, 2022, 08:03:53 pm »
Wow, glad I had a quick look at this thread this morning befdore hurrying to work, I was able to send the seller a message to cancel the deal in time ! Mercifully he was very understanding/forgiving, no drama .  :phew:

I am ust say UI ma surprised that a VGA monitor can't display EGA, I mean lower resolutions in general, since the H/W is capable of it ? I mean you can't ask a 14" monitor to display what a 21" CRT can, because it simply doe snot have the H/W ressources, the bandwidth to do it ! But a 21" can of course display lower resolutions like 1280 or 1204 or 800 or even 640/VGA of course..... similarly I was assuming that any VGA monitor could display preceding video standards like CGA/EGA.

I also just found this Wikipedia page about EGA which does say that VGA did support EGA :

https://en.wikipedia.org/wiki/Enhanced_Graphics_Adapter

Anyway... I don't really have the space for a CRT monitor, and I will gladly buy that 20 buck gizmo from Aliexpress to let me use my existing VGA LCD screens.

Not a big fan of composite, because not all my monitors have it, and those that do, I have had mixed fortunes trying to get them to display the composite output from an old VCR I was working on earlier this year.  However VGA seems to be present in just about any old LCD screen I get passed, and all of them manage to display the VGA signals I send them, be it from a computer of from my old Tek scopes.

OK so I will buy that gizmo, first try to find it on the French version of Aliexpress or other reseller... this will probably take 2 to 3 weeks to arrive, as per usual... so in the meantime I will be able to get back to my other projects / activities.  SO, dummy load DIY and PSU fixing.... old man is a bit pushy about me fixing it.

 

Offline VinceTopic starter

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #43 on: November 02, 2022, 08:08:39 pm »
Forgot.

So since VGA is about 30kHz Hsync, for 640  pixels wide, and the programmer is about 15kHz.... I guess that means the video output on the programmer is 320 pixels wide, half VGA ? Is that how it works ?
Yes I am not too clued on the technical details....

I noticed that if I divide Hsync frequency by the Vsync one, 15.000 / 46.5 , I get 320 pixels hmmm....

 

Offline VinceTopic starter

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #44 on: November 03, 2022, 08:27:29 pm »



OK I just bought that 20+ Euros video converter... from Ebay not Aliexpress. On Ebay I found a seller that's based in France and has stocks locally, so I should receive it much faster than China direct, as well as being guaranteed that I won't have to pay duty taxes if I get unlucky, nor deal with any of the delays and admin BS you can get with importing anything.

So I should received it in the next few days normally, great.

In the mean time I will resume work on the electronic dummy load to fix that PSU.


Oh, last night I had some fun with my nixie counter. Wel, one of my Nixie counters.... my main one that's permanently on the bench ready to go.

Was googling to try to find info about timing of H/V sync signal for EGA/CGA, to see i i could find something that matches what I measured.

Turns out finding detailled timing info is not that easy...

The little I found suggest that my programmer uses nothing that exists !

https://minuszerodegrees.net/mda_cga_ega/mda_cga_ega.htm

The Hsync signal is supposed to be 15.7kHz, 63.7µs for CGA and EGA. but I measured 15.4 with the scope, and that's not very accurate.
So I measured it much more accurately to be sure of things, using my Nixie counter.... ideal opportuinty to show taht even my vintage counters can still do useful stuff...
It measured 15.384Hz and 65.001µs.

I read that most monitors are a little bit forgiving about timing accuracy.... so maybe 15.4kHz will still be recognized a valid 15.7kHz signal... I hope.

So let's say it's then either CGA or EGA.

Now that poses more problem : the width of the pulse on this signal, I measured 8us and this apparently can only be an " MDA "monitor "... but MDA Hsync is not 63.7µs, it's only 54.3µs !
Plus, MDA has a negative going pulse for Vsync, but I have positive going pulse on both H and V... which matches EGA and CGA specs.

So... I guess the most probable is, it is CGA but with an MDA pulse width....

But still, there is one thing that worries me... Vsync freq / refresh rate !
The programmer puts out about 46.6Hz , whereas it says taht EGA/CGA is only 60Hz !
So doesn't work...
Also, how can 46Hz even exist ? I mean it's such a low frequency that the screen would  flicker so badly no human would tolerate that !  :wtf:

So all in all my sync signals are inconsistent with old standards, it's a pot pourri.

So what I am starting to fear, though I do admit it's a bit paranoid and far fetched (so hopefully I will be proved wrong soon...)  is that this programmer was shipped with custom monitor !
One that was tweaked/specced for Micropross to suit their programmer, to make sure customers could not buy a third party monitor on the cheap to save money, maybe.

So that custom monitor had maybe a special phosphor as well, with a very high persistence characteristic to get around the very low 46Hz refresh rate.
I know, far fetched, but who knows.

In any case, not too worried... I am taking it one step at a time. I just ordered that CGA/EGA to VGA converter, so let's wait for that and see what that does for me. We will take it from there...


 

Offline pcprogrammer

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #45 on: November 04, 2022, 05:59:35 am »
Hi Vince,

I think you are overthinking it :)

It is just standard old TV signals but with the frequency slightly of. It should be 64us but the main clock might be a bit slow. Look at the datasheet of the MC6845 and see what the clock frequency is there.

Most likely the gadget you ordered will be able to handle the signal.

Edit: Early TV (PAL) worked with interlaced screens, so a full screen refresh rate was only 25Hz and our eyes did not see it flicker :-DD
« Last Edit: November 04, 2022, 06:05:40 am by pcprogrammer »
 
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Offline VinceTopic starter

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #46 on: November 04, 2022, 08:38:04 pm »
I like your optimism, may you be right, crossing fingers !  :-DD

Interlacing hmmm..... yep, forgot about this thing, good point ! Very.... good point  :-+

Got an e-mail from ebay, says the seller has already shipped the video converter.
Guy sends it via regular mail, not a parcel.
I paid 30 cents extra to get a red stamp / priority mail... so could be here on Monday !  8)

The datasheet for the CRT controller doesn't give a fixed crystal / clock frequency. It just says the clock can be " up to " 2.5MHz.
So since we have a 8MHz crystal on the board, I guess the CRTC probably runs on 2MHz... of course I could measure that.  8)
 
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Offline VinceTopic starter

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #47 on: November 07, 2022, 07:28:33 pm »


Just received my video board ordered here :

https://www.ebay.fr/itm/304639100056

... or did I ?!  In the enveloppe NO board, just the big loose connector wired to the board, but not the board itself !!  :o

30 Euros for a freaking connector and some wires ?!

OK I will return this thing immediately to get my money back..   :palm:

 

Offline alm

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #48 on: November 07, 2022, 07:53:51 pm »
My French isn't very good, but seems to me like it is as described:
Quote
Adaptateur Jamma CGA2VGA (Attention CGA2VGA non inclus)

Offline pcprogrammer

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Re: Vintage chip Programmer : " Micropross ROM 3000U "
« Reply #49 on: November 07, 2022, 08:03:58 pm »
Yes that is how I see it too. But almost 30 euros for just that cable bit is ridicules :palm:

Hope you can indeed return it and tell the bloke to make it more clear that it does not include the board within the first picture on his listing.

I guess Aliexpress looks real good now in comparison :-DD

Edit: The same seller has the needed board for just 3 euros more: https://www.ebay.fr/itm/303522687731 So maybe you can make a deal to exchange things.
« Last Edit: November 07, 2022, 08:11:10 pm by pcprogrammer »
 


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