Epson PF10 problems

I'll dig em out over the holiday and see if I can read them. Lots! ("My day job is producing development tools for a large number of embedded processors). I'd have to look at it to be certain (haven't had to write anything for it in a long time), but I'm pretty certain I used a 6402 - but you could use any of the "hardare programmable" uarts (AY-5-1013, COM2502 etc.) - You don't NEED to use a "hardware programmable" uart, but doing so means that the only thing you need to write is the data register. And with this setup, "writes" are best kept to a minimum :-) The idea is to have a "monitor" that you can plug into the EPROM socket of just about any machine, and talk to it (assuming that you write code for that particular CPU), and also to assume that the rest of the hardware is unknown, and possibly not working. It's possible to write a simple montor that does not use RAM, however you still need a way to communicate with the debug terminal - since an EPROM socket does not have a -WR line, you can't write in the "normal" sense - also, you don't want to risk contention with something else on the bus. So what I did was to generate selects for two 256 byte pages in the ROM area - reading the top 1/2 of the first page gets me two bits which are the RXready and TXready signals from the UART. Reading the bottom 1/2 of that page gets me the receive data register. Reading the second 256 byte page actually writes the bottom byte of the address to the UART transmit data register - this allows me to read/write to a terminal without having to do anything other than read the EPROM space. This lets me get "inside the bus" and be able to do basic reads and writes on most any system. No more info about my "ROM socket monitor", as I built it a long time ago, and don't even have schematics (at least I don't know where they would be) - but it is pretty simple and should not take much to replicate. As far as tools, assemblers, disassemblers, compilers, monitors etc. go - these are described and have downloadable demos on my comercial site (www.dunfield.com) - Yes, I generally expect people to pay if they want a complete package, however I often give individual component tools to people who are doing a worthy cause (like fixing a classic computer) and have a specific need. Dave -- dave04a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Collector of vintage computing equipment: http://www.parse.com/~ddunfield/museum/index.html