• Please review our updated Terms and Rules here

KIM AIM SYM eprom programmer card

Years ago, I sent a KIM-1 EPROM programmer card to John Keys for inclusion in his collection. My recollection is that it handled 3-rail EPROMs (e.g. 2708). I don't know what became of it after it went to John.
 
This one does have selection switches for different EPROMs but I think this is for the 2716/2732 and similar.
It does have a boost circuit but I suspect that is for programming voltage. There are 2 pots to adjust and they are connected to the select switches.
Dwight
 
Mine was nothing like that--blue PCB with a 44(?) pin edge connector. I may still have the small power supply that I built. This was a very early design.
 
Thanks Chuck
I guess I'll need to play with it some. I need to ohm it out to see which switch positions are mutually exclusive. My meter tells me that there several sets like that. It has a boost circuit to produce the high voltage and a 723 voltage regulator. I suspect the EPROM runs it. It would be nice if the ROM has some ASCII to give hints. I'll have to look.
The address switch has 10 selects: 1 thru 7 the B,C,D.They go to a '154.
Dwight
 
I've finally had time to disassemble the code on the programmer board. It runs at 9000H and calls routines in the AIM65 monitor. So, without significant modifications, to the code, it won't directly run on a SYM or KIM. It looks like it also was written with the intent of keeping many of the same command structures that the AIM monitor used. I have an AIM65 but I'd have to dig it out from storage as well. I don't see anything about the jumper setting in the code, at least there are no messages there, other than just running the code and transferring data, using the monitors I/O routines.
Dwight
 
I'm made good progress on the programmer card.
I wanted to use it on my SYM-2 orSYM-1. It had a EPROM on it that was clearly for an AIM65. I'd assumed it was code to run the programmer. It clearly isn't.
First the EPROM is a 2732. I see that pin 21 is hard tied to VCC, as would be typical for a 2716. I was wondering how the code that was in it could be addressing the other addresses of the programmer card.
As I said in another thread, my SYM-2 looks like it may have been a prototype of a SYM-2. There were several things that were not quite right. The RAM had multiple repeated addresses across the low memory. I wanted to use that space so wanted the RAM to only be active in the low memory as a SYM-1 would do.
After some circuit tracing,I found that I could correct the addressing by adding a 74LS27 to the board. There was an unused socket location that I wired in the '27 to full decoding. I also had to change the programmer cards addressing, as it decoded part of its address at 8000h. That overlapped the SYM-2/1 monitor ROM space.
That required couple cuts and a couple jumpers, to move that decoding to 6000h. ( It has a nice 74LS154 there for moving the address select around )
The card was still not responding so I started tracing what was missing. I traced it to pase2* missing.
Back to the SYM2 board and found nothing wired to pin Y of the E connector. A little bit of circuit tracing and I found a 74LS04 Phase2* signal ( often used for many things ) on the board and wire up pin Y.
The programmer card now seems to be responding. It has 2 RAMs on it that I find at 7000h and the ROM image is found at 6000h. I'm thinking the programming controls are likely at 8000h, as that address is hard wired to the 74LS154. I can now explore what it might be doing and what particular addresses in the 8000h bank.
As I noted, I now realize the code I found in the EPROM was not for the programmer as it over flowed into a space that is out side the range of a 2716, as the socket is wired for.
Dwight
 
You must log in or register to reply here.
Back
Top