Author Topic: Burning 8K audio-data into 4K EPROM (truncated)  (Read 652 times)

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Offline analogix

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Burning 8K audio-data into 4K EPROM (truncated)
« on: March 14, 2018, 06:41:04 am »
I'd like to burn (program) audio data from an 8K (2764) EPROM binary (.BIN) file into a 4K (2732) EPROM but the programmer won't let me.
It's for a digital drum machine, and the 8K audio still sounds fine even though you only get to hear the first half. 


I'm using a Minipro TL866CS EPROM-programmer but it gives me an error message when I try to burn (program) it. What do I need to do in order to burn the 2764 data (the first half of it anyway) into a 2732? Here's what I've tried:

1) Select 2732A as the EPROM type I'm using

2) Load the 8K BIN file into memory, where I use these default values:

File format: Binary
To region: code memory
Load mode: normal
From file start addr (hex): 0000
To buffer start addr (hex): 0000
Clear buffer when loading the file: clear buffer with default


3) Next I go to the "Program" menu with these default values:

[x] code memory
Start addr: 00000000
End addr: 00000FFF

4) when I press the "program" button I immediately get the following error message:

ERROR! Address: 0x000000 Buffer data: 0x00  Verify:0xFF

Offline BrianHG

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Re: Burning 8K audio-data into 4K EPROM (truncated)
« Reply #1 on: March 14, 2018, 06:56:43 am »
You can try loading the file with an 8k eprom, do not program, just select the 8k eprom in the programmer.  Then, save a new .bin file & when you are asked to save, save @ starting address and length, only save the first half.

The other option is use a file hex editor which allows you to load your original file, you then cut/delete the second half and re-save the new 4k file.

Here is a free hex file editor (It's always good to have such a tool lying around): https://www.hhdsoftware.com/free-hex-editor
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Offline bson

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Re: Burning 8K audio-data into 4K EPROM (truncated)
« Reply #2 on: March 14, 2018, 12:17:33 pm »
Dump the first 4k of the 8k EPROM to a file, then write the 4k file to the 4k EPROM.
 

Offline BrianHG

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Re: Burning 8K audio-data into 4K EPROM (truncated)
« Reply #3 on: March 14, 2018, 01:11:06 pm »
You can also try reading your 8k eprom, but selecting the 4k device.  You might still get the first 4k of data correctly.  Then save that file & burn your new 4k file.
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Offline analogix

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Re: Burning 8K audio-data into 4K EPROM (truncated)
« Reply #4 on: March 14, 2018, 04:41:09 pm »
Good questions, as I tried a variety of things yesterday which all didn't work. Needless to say I'm not very experience with the software, and all I've done so far is either read the contents of EPROMs and save them as BIN files, check if an EPROM is blank or write to a blank EPROM from a BIN file given by others online. It's all worked fine.

In this particular case I'm trying to read an 8K file, then write it to a blank 4K EPROM.
Since none of this works I'm going to try and write a 4K file to that same EPROM, just to rule out any other issues. The EPROM did contain some (fully working) data prior to my recent attempts, so I assume it's still OK after I erased it, but your suggestions prompted me to check it all out, so I'll try to write a 4K file to that 4K EPROM as properly intended, to at least rule out if the EPROM has gone south or there's something fundementally wrong with the software or hardware.

Bson and BrianHG: I've tried most of those suggestions, but nothing appears to work (or I'm just not experienced enough with the software). Having a "Chinglish" translation of a highly technical product doesn't really help either  ;)
Oh, I did download a couple of hex editors for the Mac platform (I'm most comfortable with the Mac -I have the EPROM programmer software installed under a separate Windows boot option on the Mac). I believe it should work in much the same way as the software you suggested BrianHG, but I'm having a hard time figuring the address position and basic copy/paste out. There's also some basic editing options in the EPROM software itself, but I don't seem to be getting anywhere.

I'll be back with the results of my "standard" EPROM testing.
« Last Edit: March 14, 2018, 04:48:28 pm by analogix »
 

Offline ebastler

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Re: Burning 8K audio-data into 4K EPROM (truncated)
« Reply #5 on: March 14, 2018, 05:51:29 pm »
Are you trying to program "classic" 2732, i.e. a UV-erasable EPROM?

Correct me if I'm wrong, but don't these require 25V programming voltage, and isn't the TL866 known to be incapable of that? Some users have reported success at 21V programming voltage, although that is out of spec for these old EPROMs, I believe.

http://www.insentricity.com/a.cl/196/ItsNotStupidItsEnhanced
 

Offline Mp3

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Re: Burning 8K audio-data into 4K EPROM (truncated)
« Reply #6 on: March 14, 2018, 08:34:46 pm »
I have a TL866CS and get this error when attempting to over write a single time writable ROM, or a non erased UV EPROM...
 

Offline mikeselectricstuff

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Re: Burning 8K audio-data into 4K EPROM (truncated)
« Reply #7 on: March 14, 2018, 09:05:58 pm »
I have vague memories that the 2732 was before manufacturer's programming specs aligned with each other, and there were some differences between 2732's from different manufacturers
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Offline analogix

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Re: Burning 8K audio-data into 4K EPROM (truncated)
« Reply #8 on: March 15, 2018, 12:06:53 am »
Are you trying to program "classic" 2732, i.e. a UV-erasable EPROM?

Yes, that's correct. I use a specialized UV-lamp (a small fluorescent tube) I've had since the early 80s for erasing. Still works fine. Takes me about 10 minutes to completely erase a chip.
The particular EPROM I'm trying to program now is an Intel D2732A-3.


Quote
Correct me if I'm wrong, but don't these require 25V programming voltage, and isn't the TL866 known to be incapable of that? Some users have reported success at 21V programming voltage, although that is out of spec for these old EPROMs, I believe.

http://www.insentricity.com/a.cl/196/ItsNotStupidItsEnhanced

You nailed it!
That solved my entire problem. I did actually look into it (because on the EPROM it says "PGM AT 21V"), but I believe I've used 12.5V with other EPROMs so I found this a little strange.
So I found its datasheet (it actually just says "2732A" but I suppose it's the same thing). I often find datasheets complicated to read and I must have misunderstood something because it says "Vpp supply voltage with respect to ground during programming: -0.3 to +22V" but re-reading the document this was under "absolute maximum ratings" and elsewhere I see that it says "In the program mode the OE/Vpp input is pulsed from a TTL level to 21V" which I guess is just a detailed technical way of saying that its programming voltage is 21V  ;)

Fortunately the TL866 software allows me to use a maximum of 21V (you're right about the absence of 25V) so all I did was:

1) Select the correct EPROM type (24-pin 2732A)
2) change the "VPP voltage" to 21V (I think it was at 12.5V by default)
3) load the 8K (2764) BIN file
4) burn (program) the EPROM

3 seconds later... bingo! no error message and everything worked as it should. I even tried it out in the drum machine. Sounds great!
Such a simple solution. It sure would have helped with properly translated software, but I guess you get what you pay for  :P

Nice blog link. Brings back memories with the Apple II. It was mostly 2716 back then and I even had an EPROM programmer for it! I think it took 2716, 2732 and 2764 chips.

So, since there apparently was no programming voltage standard back then I assume we need to look up every single EPROM's datasheet before burning (or we might end up literally burning them out!). It's probably a good idea to write the programming voltage with a white marker on each chip.



Oh, a final question: does anyone know where you can get low profile ZIF sockets (for quickly/easily exchanging EPROMs)? It should extend no more than 10mm (absolutely maximum 12mm) from the PCB and have 28 pins. They sell them at the DMX files for US$ 12.50 each, but apart from the initial high cost there's the usually very high shipping cost from the United States which doesn't justify most purchases.
Does anyone recognize that black low-profile ZIF socket in the link and know if anything similar at lower cost is available? Of course it has to be of reasonably good quality (for home use) although there's no need for "industrial quality" for millions of repeated insertions at a premium price.
« Last Edit: March 15, 2018, 12:36:01 am by analogix »
 

Offline ebastler

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Re: Burning 8K audio-data into 4K EPROM (truncated)
« Reply #9 on: March 15, 2018, 12:19:34 am »
Hey, glad you got it to work!

I looked it up in the meantime, and the 2732A is indeed the first generation of EPROMs which the TL866 can program, at 21V programming voltage. The original 2732 required 25V, and hence can't be programmed with the TL866. (At least not reliably; some users have reported success by re-writing multiple times.)

As Mike mentioned, for those early generations of EPROMs there may be subtle variations even for the same part number, depending on the manufacturer. I don't recall in detail, but I believe that either Intel or TI were the culprits who made 27xx parts with different programming algorithms (or even different pinouts?!) than everybody else's. They came out with a 25xx series later which was in line with the competitors' 27xx chips, I believe. So better check the specific manufacturer's datasheet for those old EPROMs...

EDIT: It was worse...
TMS2716 (Texas) = exotic, needs three voltages to program
TMS2516 (Texas) = 2716 Intel (and other)
TMS2532 (Texas) != 2732 Intel (and other), different pinout...
http://www.tomshardware.co.uk/forum/80532-13-what-diff-eprom-eprom
« Last Edit: March 15, 2018, 12:42:27 am by ebastler »
 

Offline ebastler

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Re: Burning 8K audio-data into 4K EPROM (truncated)
« Reply #10 on: March 15, 2018, 12:58:49 am »
Oh, a final question: does anyone know where you can get low profile ZIF sockets (for quickly/easily exchanging EPROMs)? It should extend no more than 10mm (absolutely maximum 12mm) from the PCB and have 28 pins. They sell them at the DMX files for US$ 12.50 each, but apart from the initial high cost there's the usually very high shipping cost from the United States which doesn't justify most purchases.

Does anyone recognize that black low-profile ZIF socket in the link and know if anything similar at lower cost is available? Of course it has to be of reasonably good quality (for home use) although there's no need for "industrial quality" for millions of repeated insertions at a premium price.

I have some no-name ZIF sockets with a "slider" mechanism, similar to the black ones in your link, which are pretty dreadful. The force/friction to actuate the mechanism is way too high, and it is hard to do so without exerting a lot of sideways force on the socket and PCB. I have unintentionally pushed the ZIF socket out of the PCB's socket in the process, bending a lot of pins... There may be great quality look-alikes around, but based on my bad experience I have generally shied away from this type.

In contrast, even low-cost clones of the 3M/Textool socket (the greenish one in your picture) have always worked nicely for me. I would not hesitate to order some from Chinese ebay sellers. They may, however, be higher than 12mm; I don't have any of them handy to measure right now.

If you need to re-program often for testing purposes, it may pay off to get some 28Cxx EEPROMs, by the way. No more waiting for UV easure cycles! I have had good success with the Atmel AT28Cxx series. They even start at 28C16 size (available as old stock on ebay etc.), enabling you to program 16 kBit EPROMs with the TL866.
 

Offline analogix

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Re: Burning 8K audio-data into 4K EPROM (truncated)
« Reply #11 on: March 15, 2018, 09:08:17 pm »
I didn't know things were that bad in regards to pinouts in addition to different programming voltages. So far I haven't experienced different pinouts, but better check first. At least I hope the swapped pins are just signal pins and not voltage pins so I don't end up accidently frying something.

I've never tried electrically eraseable types (EEPROMs) before, but this sure would be a good solution if I need to reburn a lot. I suppose the electrical erasing is done with the EPROM programmer?
Are those 28Cxx series directly compatible with "old school" EPROMs such as the 2732, 2764 and 27128?

I think I've found the black low-profile socket I referred to earlier. It's the 526 series by Aries.


But the one you've had bad experiences with is just one that looks similar to it, right? Those Aries sockets are pretty expensive (the cheapest I found online are around US$ 10 each, but either they don't ship outside the U.S. or shipping is very expensive). Does anyone know if there are low-cost versions of the above, or someone selling them outside of the U.S.?

Yes, those 3M Textool clones from eBay etc. are probably OK for home/hobby use, but they're just a little too high (10mm, and I have to add the EPROM height on top of that).

Offline ebastler

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Re: Burning 8K audio-data into 4K EPROM (truncated)
« Reply #12 on: March 15, 2018, 09:53:59 pm »
I've never tried electrically eraseable types (EEPROMs) before, but this sure would be a good solution if I need to reburn a lot. I suppose the electrical erasing is done with the EPROM programmer?
Are those 28Cxx series directly compatible with "old school" EPROMs such as the 2732, 2764 and 27128?

Yes, they simply get erased in the programmer, and once programmed are directly compatible with the old EPROMs. (As an added bonus, if the original ROMs in a vintage board were mask-programmed or one-time programmable ones in a black plastic DIP package, the 28Cxx types look more "correct" than the windowed UV-erasable packages!  ;))

Quote
I think I've found the black low-profile socket I referred to earlier. It's the 526 series by Aries.

Ah, there is a proper lever after all in the Aries socket! I had misinterpreted the picture under your earlier link. The type I have bad experience with is operated via a plastic slider which gets pushed in and out horizontally. No leverage, and too much sideways force... I can't even find pictures of these online anymore, so they seem to have gone fully out of fashion (thankfully!). So please ignore my comment; I'm sure the Aries socket will be fine.
 


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