Willem programmer produces faulty eproms

[hwa]

All, I'm using Willem programmer board v5.0 ,but a tad newer refresh. Instead of two 3,5 mm leds on lower left corner I have 3 surface mount leds. Also there are lots of SM chips. Maybe this is relevant, maybe not.

I use B0.992D (DOS) version of the Willem programmer software, as this, my ancient computer and the stupid PCI LPT-port add-on card with AXIS chip, is the only combination I could get the programmer board to be recognised with the programmer software. Win7? No! XP? No! LOL. So DOS it is.

Programmer finds the board and I can set the chip to 27c256, which I have, and I can read chips and verify they're empty. Now the target is to burn a newer Apple Iic ROM to 27c256 chip. Partly that works but only partly. The FF first bytes from the image file are written all over and again to fill the eprom. And naturally this won't work too well.

The image file looks perfectly ok. At 0x100 the actual program code begins. Before that there is bunch of peoples names. File is http://mirrors.apple2.org.za/Apple .../ROM Images/Apple IIc ROM 04 - 341-0445-B.bin

What causes this behaviour and how to correct it? Please note I'm on UTC+2 TZ, so answers may get postponed till next day.

 

[ldkraemer]

Your Willem Programmer should have later software than what you are using. My Willem uses ver 6.x
for a Version 6 PCB.

You have to set the device configuration switches, plus the correct jumpers for the Power Supply voltage
etc.

I have attached a Photo of what I would be required to set to write a 27C256 EPROM.

I use Debian Linux and run that Software in DOSBox. My Tutorial is at:
https://forums.debian.net/viewtopic.php?p=737109&hilit=Willem#p737109



Larry

 

[ldkraemer]

Your Start of Buffer is CORRECT and so is the End of Buffer. I have attached those
pnoto's.

Are you plugging directly into the Parallel Port or Using a straight through cable?
How long is your Cable, if one is used?

Larry