| Electronics > Repair |
| Vintage chip Programmer : " Micropross ROM 3000U " |
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| pcprogrammer:
You need a small table on wheels to roll stuff in and out :-DD But however big your bench is, there will always come a time that it is to small :palm: |
| Vince:
Sadly there is zero space to fit a table, never mind wheel it around. Only place in the house where is space to put stuff and use it is... the bench itself.... and it's gonna stay like that for at least 2 or 3 years, the time to build the garage to I can shift stuff into there and make room in the house. |
| Vince:
Geez.... I think I managed to make something that might work we shall see. I got lucky and foudn my spliced serial cable, woohoo !! I am so glad I was clever enough to keep it when I was sorting through boxes and boxes of old cables.... most likely thanks to one of you who must have explained to me what these cables were for... Anyway. so with this cable, plus my previous light blue flat cable (ex RJ45 cable for serial consoles IIRC...) that I sacrificed a few years back so I could cut the connector and strip the wires so I can scope the signal.... plus 3 gender changers..... look what we get as a result ! A spaghetti monster ! But.... it works, then it's gonna be TASTY spaghetti hmmmm !!! >:D I am tired of all thyis messing around with cables and gender changers....it's official, I just added another little design project to my list.... I will make myseld a little breakout box so that I can spy serial links with much less mess, a much more compact and convenient setup..... I could fit ti with both 9 and 25 pin connectors on both the input and the output, so that the worse I might need to do would be a gender changer, that's OK. Then LEDs to see the activity on the various signal, and easy test points on which to hook a DMM or scope probe.. and also some jumpers to easily swap lines where useful. and myabe a small prototyping area as well, you never know what you might need eh ! >:D Yes, I need that... I want that... I wiiiiil make that thing... one day. OK so let's try my monster cable see if that works somehow... |
| Vince:
OK, we have results here.... I put the programmer back onto the bench with the HP scope sitting atop. The compactness of the HP scope does wonders. The bad : my spaghetti cable doesn't work, the PC fails to communicate with the programmer... investigations are required.... |O The good : even if the programmer does not talk, the simple act of plugging the other end of the cable to the programmer, made the PC S/W happy : now it DOES send stuff "in the air"... so I was able to capture that and work on it. So that means as I feared, that the MS-DOS program does use H/W control lines, not just RxD / TxD, bummer. - It sends always the same frame, it's perfectly repeatable. - Frame lasts about 5.5ms - Bit time measures at about 103.75us so now we know the baud rate : 9,600 bps. It was not so accurate when measuring a single bit, because you have the problem of deciding where to place the cursors on the leading and trailing edges, because you can actually see the slope of them. So in order to minimize this problem, I measured a group of 4 bits to get the figure above. - That means the frame contains about 53 bits. - We assume that frame of course must correspond to what we saw on the "terminal" screen of the programmer : " BOOT + <CR> " , so 5 characters. - So that's about 10 bits per character... it adds up so far. - So then I converted " BOOT + CR " into binary and scrolled the stream of bits one by one, hoping to find matches and hoping I could figure out how many start/stop/ parity bits we have. Here is the very first character as an example, so it's a 'B'... was happy so kept going 'til the end ;D Well it all went OK and that frame indeed contains " BOOT + <CR> " , and we have one start bit, no parity bit, and an idle time between characters of 2 bit "slots". So I guess that means 2 stop bits. So " 9600 8N2 " >:D So now I can configure a terminal and talk directly to the programmer yeah... but no. Again, I need to figure out the extra control lines used by the interface, and I know squat about that. So I will probably never figure that out hence terminal fun is not going to happen. |
| pcprogrammer:
Hi Vince, the hardware handshaking is not that tricky. I vaguely remember having three options for hyperterminal. No handshaking Xon / Xoff Hardware handshaking Your cable has to have the lines connected because the software for the programmer is able to query the version, so just give it a try 8) Edit: Yep checked it in a virtualbox Windows XP setup. |
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