A plan for a "universal" low-pin-count programmer

Hi guys, I know a few folks here (besides myself) have accumulated collections of older-generation (i.e. "obsolete") fuse-PROMs, GALs, PALs, and so on. A common complaint is that modern programmers won't touch these devices -- negative voltages (sometimes very high negative voltages) are required to program some of them, and for others the programming hardware just wasn't tested with them. In my experience, when confronted with the fact that their programmers don't actually work, most programmer manufacturers seem to respond by asking why you're even thinking about using 1702 EPROMs in their programmer, and sooner-or-later admit that they actually didn't test them on anything more recent than a programmer they last sold in the late 1980s, and that they "just ported the software across and thought it would work". So what I'm proposing is this. A completely open-sourced device programmer. That is, all the hardware designs, PCB layouts, software and firmware are (or at least will be) completely open. My "rough feature set" boils down to: * Single input power supply -- probably 24V DC. Fed from a normal mains adapter. I'm tempted to use 12V DC instead, and live with the higher current consumption -- my only spare 24V PSU is a massive 600W Nemic-Lambda dual-fan unit that makes a sound not unlike that of a mid-sized jet aircraft. 12V 2A power supplies are a bit more plentiful... * Two programmable positive power supplies, all variable between around 2V and ~24V (or higher if need be). Maybe add a third if necessary (for ECL maybe?) * Two programmable negative power supplies, variable between -2V and -50V. Meaning you can program 1702s with it. * 24, 32 or 40 individually-programmable pin drivers. More or less if you like -- add or remove a few pin drivers. I think the upper maximum is likely to be around 64 pins, based on typical CPLD pin counts. * Modular design -- one interface controller (computer -> driver interface), swappable power supply boards, pin count can be increased in 8-pin blocks by adding more pin drivers (or boards can be swapped to troubleshoot driver issues). There is one obvious limitation here -- you need the programming algorithm for the chip you want to program. The algorithms for MMI PALs are (I've been told) in their databook, the Signetics algorithms (for fuse-PROMs) are just as easy to find, and TI put their TIBPAL programming algorithms on their website. Things like Lattice GALs might be difficult, unless you could live with using an "unofficial" programming algorithm (*cough* GALBlast). I suppose you could reverse-engineer an algorithm from a working programmer and a minimum of two blank chips, but I suspect something like the GAL algorithm (in complexity) might be somewhat tricky to reverse-engineer. Does anyone (besides me) think this is a worthy endeavour? At the moment I'm thinking of using FET-based pin-drivers (lower pin count and voltage drop, potentially faster switching) and MC34063-based switch-mode PSUs. The control interface will likely be USB, possibly based on a Cypress EZ-USB FX2LP chip -- the advantage being that the firmware is stored in the MCU's RAM (uploaded from the PC on startup), so no PIC, AVR or 8051 programmer is required. Unless anyone has any other comments or suggestions? Cheers, -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/