Programming a PAL/PALCE ICs

[rpalmer]

Hello All,

I have been on the internet looking for a PAL/PALCE device programmer and quickly found none exist.

I did find GAL Blast, but it states that it cannot program a PAL/PALCE. I did notice that many references to PAL programming also refer to GAL blast, so it confuses me as to how, since the author says it cannot.

I have also looking for a source of GALs, but the main sources (RS, Element14, mouser, futurlec, etc) state that they are no longer available. PALs on the other hand are available.

The need for PALs is for my attempt to create a memory expansion (2Mb).

So my question is, has anyone found (prefer DIY build) of a PAL/PALCE programmer?

Any advice would be much appreciated.

rpalmer

[pelrun]

GALblast will do PALs; it's the PALC/PALCEs from AMD it can't handle.


CPLDs are another option; they're cheap and readily available. But they're almost all 3.3v logic, so you need to deal with that. It's not insurmountable; TotO's X-MEM uses one.

[TotO]

PAL/GAL programmers are easy to find on ebay.

About your expansion, I suggest that you mean 2MB and not 2Mb?
If you plane to use it exclusively on a 6128, you should build it with few logic ICs to handle four 512KB slots on ports #7Fxx, #7Exx, #7Dxx, #7Cxx without using programmable devices. Else, it should be better to use a CPLD to embed all the logic.

[rpalmer]

TotO,

Thanks for pointing out that it is 2 MB not 2 Mb.

The GAL/PAL is to provide the required logic for each mode like that of Dk'Tronic memory expansion kits and internal memory expansion of 6128. A CPLD would not be required as the GAL/PAL would be used in 'combinatorial' mode. If I were to use DRAM then yes a CPLD might be a better choice, but intend to use a single SRAM chip (2048K x .

My version of the expansion will also make use of A8/A9 to get more addressable memory.

See attached draft of memory expansion details.

rpalmer

[TotO]

Using a CPLD allow to reduce the size by embedding the "PAL" and the other ICs.
But sure, you should do like the DK'Tronics and only use the PAL for the C* modes + 7 more ICs for the logic.

Your draft look OK and the use of A8 and A9 is well done too. (I handle A8 like that on X-MEM to allow 2 boards)

Good luck!