The promice ROM emulator - cables, jumpers, and pinouts

Switches and Jumpers

The switches tell it what size ROM it is emulating. You set all of the switches for your size rom and smaller to "ON".

Then on the other side of the place you plug in the ribbon cable are a bunch of jumpers. The first 4 tell it where it should get power from. I usually install the "EXT" jumper and use the little 9 volt wall wart. You can let the promice get its power from the ROM socket (they say it only draws 120 mA). If you do, you set a jumper to "24" or "28" or "32" according to the number of pins in the device you are emulating.

A note on the wall-wart. The one I have is a 9 volt, 200 mA device, which seems barely adequate. Indeed the manual says that a 500 mA device should be supplied with the unit. The manual also says that the unit should draw less than 120 mA, which would lead one to believe that the 200 mA device I have (and who knows where it came from) is actually adequate. What makes me nervous is that the power LED on my unit blinks off and on. This could be a bad solder joint on that LED or some such. Stay tuned.

Important note: Be very sure you identify pin 1 on the socket and the cable and get it plugged in right. Getting this wrong will cause something to get damaged. You have been warned! There should be a red stripe on the pin 1 side of the cable, and if you are lucky a sticker on the plug that goes into the ROM socket that marks pin one. If you haven't figured out how to identify pin 1 on a chip or socket by now, you are probably in the wrong business. Here is a hot tip! Get a PC socket with 24 or 28 or 32 pins (as needed) and press it onto the plug, then plug that into the socket. This way when pins get bent someday (since you will plug this thing in and out fairly often) you can just get a new socket rather than having to repair the plug on the end of the cable. You will thank me someday for this advice.

There are 6 more jumpers which I never use (12 pins all told).

• ACK and REQ - used with the PiCOM protocol, which I never use.
• NMI - used by the AI systems hardware trap feature (I never use).
• RST - a very handy line you can use to reset your target system.
• HSO and HSI - (handshake out and in) - for PiCOM, which I never use.
• WRT - a write line, you can use for RAM emulation, could be handy
• XCS - for AI system (Analysis Interface?) - I never use.
• A20 and A21 - for AI system, I never use.
• A22 and A23 - for AI system, I never use.

I would like someday to use the the WRT line (which allows you to bring a write strobe from your target system to the promice). The idea here is that you can set aside an area in your ROM image which is actually writeable RAM and communicate back with your host system. A cool idea, but will require some clever software support. I should look into it someday perhaps.