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Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment.

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Old 18th May 2023, 6:45 pm   #41
Pamphonica
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Default Re: Unhappy AIM-65

That’s a useful data book. Lots of AIM-65 info.
By the way, here is the “graveyard” for the AIM-65 repair. The chips ant the top are originals, all dead or faulty. The three others are potential replacements that checked out faulty as well! All clearly marked as dead to avoid confusion. They can now be binned.
-Jerem
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Old 18th May 2023, 8:12 pm   #42
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Default Re: Unhappy AIM-65

I tend to keep defective chips removed from vintage boards, just hoarding I guess, but part of the history of the machine.
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Old 19th May 2023, 9:19 am   #43
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Default Re: Unhappy AIM-65

I suppose it’s like those nasty caps I replace on radios but keep in a small bag with the set! Somehow chips seem less important though, as they may well have been replaced before. But point made- I’ll probably keep the original faulty 6532 that was the main problem.
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Old 19th May 2023, 6:18 pm   #44
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Default Re: Unhappy AIM-65

…and now it’s broken again! Don’t you love old tech… no sign of boot up messages.
RAM is OK, incl RIOT. ROMs look fine and have correct contents. Memory map looks correct. All voltages fine.
No time to work on it more before Retrotech so next week will see further activity.
Ho hum.
And BT have killed my Broadband inadvertently. Dependent on mobile for now. Stressful.
-Jeremy
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Old 19th May 2023, 6:32 pm   #45
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Default Re: Unhappy AIM-65

Maybe its the socket for the 6532 making a poor connection, try pressing down on it while powering up.
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Old 28th May 2023, 11:41 pm   #46
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Default Re: Unhappy AIM-65

No, after a lot of further testing, I’m pretty sure that the Fxxx 2332 Monitor ROM has gone flaky. It fails testing and shows errors vs the binary I have, as if various data lines are getting stuck, but not consistently. Currently up to my whotsits in EPROM programmers and adapter boards trying to get a good version working in its place. Don’t you love Old (er)tech?
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Old 29th May 2023, 1:07 pm   #47
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Default Re: Unhappy AIM-65

Success - again!
I finally got my ageing brain around all the pinout differences between 2332/2532/2732/2764 devices and finished debugging my adapter board. Having blown a good binary of the 2332 Fxxx Monitor ROM into a handy 2764 and plugged it in, all is working again. Ruddy bit-rot!
The other Mask ROM (Exxx Monitor) is still OK but who knows for how long!
I would like to end up with the Monitor blown cleanly into a pair of 2532 pin-compatible EPROMs. However, I can't blow 2532s without an adapter to make them look like 2732s for my EPROM programmer, and my nice TL866II programmer cannot produce enough volts to program 2532s anyway, so I am going to have to burn a 2764 on the TL866, move that to the Dataman S4 and load it, then see if yet another adapter board will allow the S4 to blow a 2532 correctly.

-Jeremy
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Old 29th May 2023, 3:12 pm   #48
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Default Re: Unhappy AIM-65

Great news on the repair - it is a real pain the early non JEDEC layout devices and the high programming voltage / unusual procedures but, a big part of the vintage experience.
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Old 29th May 2023, 6:56 pm   #49
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Default Re: Unhappy AIM-65

Quote:
I can't blow 2532s without an adapter to make them look like 2732s for my EPROM programmer, and my nice TL866II programmer cannot produce enough volts to program 2532s anyway, so I am going to have to burn a 2764 on the TL866, move that to the Dataman S4 and load it, then see if yet another adapter board will allow the S4 to blow a 2532 correctly.
Or you could phone a friend.

I have a Dataman Mempro programmer here which I believe can program several Hitachi and T.i. versions of the 2532, happy to programme one for you - no charge implied - if you can furnish me with a suitable 2532 device.

There are others here too who can programme 2532 devices.

There is also forum member 1908s_john who can probably sell you a programmed 2532 device for a reasonable price, all you have to do is email him the file or point him at it on the internet. The advantage of this approach is that 1980s_john has genuine old stock EPROMs and will programme an EPROM with the code and verify it before sending it off to you, whereas trying to buy old EPROMs to send to someone else to have programmed can be a complete nightmare as the rarer / older types are so commonly faked.

I confess I'm a little bit surprised that the S4 (A decent programmer, to be sure) doesn't support any variant of the 2532, device support list here

https://www.dataman.com/mwdownloads/...ad/link/id/17/

However, my Dataman Mempro does support a couple of Hitachi and a couple of Ti (TMS) versions of the 2532 - specifically, I don't see the Ti TMS2532JL supported in this list but the TMS2532 and TMS2532A are supported, as are the Hitachi HN462532 and HN462532G.

https://docs.rs-online.com/1f7d/0900766b815d0a1f.pdf
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Old 30th May 2023, 9:48 am   #50
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Default Re: Unhappy AIM-65

Actually it was not too traumatic to get some 2532s programmed. I just needed to construct an adapter to make them look like 2732As. Then they programmed fine on the S4. The S4 library I am using only has the 27xx variants, as per the link above. Anyway, I have now replaced both Monitor ROMs with EPROMs, as it is clear that the originals can get stressed and go faulty. The faults looked like address line problems, but not always exactly the same ones when tested - strange. Maybe some “leakage” between lines on the die.
It has been an interesting exercise. Aided enormously by my £5 “bus tester”!
I have put all original devices back in that are still working.
My next cunning plan (just because it sounds interesting) is to see if I can get a Commodore 1541 disk drive working from the AIM65, and probably also get cassette program saving working. I have ordered an interesting AH5050 interface board clone with EPROM from the states. It breaks out cassette interfaces and a disk interface, and saves me a lot of veroboarding. Maybe I’ll now start a parallel thread called “Happy AIM-65”, for as long as it keeps working!
Thanks all, for the offers of help.
-Jeremy
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Old 30th May 2023, 10:50 am   #51
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Default Re: Unhappy AIM-65

At some point in the future even the data in those new EPROMs will fade - it will be a long time, probably some 40-50 years after we are all gone but it might not be a bad idea to do hard copy print outs of the hex code in both EPROMs and shove them in with the rest of the documentation, who knows who might still be trying to keep that machine going all those years from now?

Anyway, I'm glad the once unhappy AIM 65 has now cheered up, and we look forward to seeing what it gets up to in the near future. The project to get it working with the 1541 drive sounds especially intriguing.
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Old 30th May 2023, 1:02 pm   #52
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Default Re: Unhappy AIM-65

I did notice that the Dataman S4 manual (Should still be downloadable from their S4 resources area, if you haven't got an original printed one - as well as the latest S4 Library ROM they released: https://www.dataman.com/dataman-s4-resources ), covers adding your own custom EPROM type to its library. And does come with a list of the programming-parameters of the originally included ones.

But I'm not sure if it gives you ability to map pins, to cope with nOE / nCE swapping around (or even changing polarity on some customised Mask ROM's, when wanting to read these), or just allows you to change programming voltage / timings (that their original Dataman 48 let you modify on existing devices).

I always made a pin-swapping adaptor, from stacked IC sockets, to deal with these.

Hopefully your 1541 has an Chinon (Alps? heads) FDD mechanism fitted, as the other Mitsumi/Newtronics type suffered from 'wire-rot' in the head, where it seems the potting-epoxy reacted with the wire and made the head go open-circuit:
https://www.c64-wiki.com/wiki/Commodore_1541

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Old 31st May 2023, 10:12 am   #53
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Default Re: Unhappy AIM-65

Quote:
Originally Posted by SiriusHardware View Post
At some point in the future even the data in those new EPROMs will fade - it will be a long time, probably some 40-50 years after we are all gone but it might not be a bad idea to do hard copy print outs of the hex code in both EPROMs and shove them in with the rest of the documentation, who knows who might still be trying to keep that machine going all those years from now?
Interesting idea! I know that the ROM binaries have been copied and are readily available currently from a number of web sites, but a hard copy might just save someone in the far future. Paper rules.

And I've checked the 1541. Peering through the bottom slots I am pretty sure that it is an ALPS mechanism, so hopefully no "head rot". Who knew such a thing existed?

-Jeremy
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Old 31st May 2023, 10:49 am   #54
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Default Re: Unhappy AIM-65

I was thinking that the likes of Hans Otten's excellent resource site and others like it are unlikely to survive for much longer than their current maintainers, and file copies of the code on say SD card, floppy or writeable CD (while also a good idea in parallel) are equally prone to deterioration / corruption and the problem of there not being anything around which can read them by the time the need arises.

A simple printout of the hex code, if kept in a light proof envelope, would very likely outlive all of these other storage methods.

While 40-50 years into the future there may still be some kind of generic programmable device which can substitute for / emulate the memory storage aspect of the original PROMs the main difficulty may be that there will be very little of it around which is happy to work with 5V levels - a problem we are already encountering now, with interfacing projects using the likes of the Raspberry Pi often needing to have level converters between the modern device and whatever old thing we are trying to interface to.
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Old 31st May 2023, 11:26 am   #55
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Default Re: Unhappy AIM-65

I keep copies of especially-rare firmware, etc on punched paper tape. This can be read, albeit slowly on an electromechanical device and can even be read, even more slowly by eye.

Of course I hope that at least one of my optical paper tape readers survives. And for day to day use, like burning a replacement chip after I've been stupid I have copies on floppy disks, USB sticks, etc.
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