*** M E M O R U M ***

PCB_Detail.png I am going to have to re-think my PCB designs again. With a home made PCB it is necessary to solder small pieces of wire between the upper and lower pads of a via. My soldering is not good enough to do this between pads at 0.05 inch spacing without creating shorts between pads or tra...

Attached is a bug fix to my implementation of the Z-Machine for MTX CP/M. Also included is a version (M576ZVM.COM) for machines with an additional 512K of RAM, which can load the entire story file into memory. Note this RAM is accessed directly, any RAM disk will be trashed. To obtain a measure of r...

Possibly, for whomever has the time. Not me, I have already got too many projects that are not getting completed because of diversions

It does not look like the source is available, so that is not a port, it would be a reverse engineer.

Including a Propeller Chip and level shifters on the Peripherals board is defenitly tight. I did not have any spare space for mounting holes. By doing some address decoding for the Propeller in the CPLD, there are some Propeller I/O pins spare, so as well as VGA out it is (from a hardware point of v...

20191227_140543.jpg Well this is an improvement on my previous attempt :) I purchased a 230 x 160 mm board from RS. That gives me two 160 x 100 mm boards, plus a 30mm spare strip to provide exposure test pieces. On close examination it is not perfect. There are places where pads are connected to th...

By totally re-writing the virtual memory code, using different algorithms, I have speeded up the program (factor of three by one estimate). However I am still not sure it is fast enough to be playable :( Profiling shows that VM access is still the bottleneck. If anyone else wants to have a hack, exe...

Martin, My Z180 project has got stalled a bit, delayed by software distractions from Memofest and otherwise. I hope to get back to it after Christmas. However, I am certainly considering making use of a variant of my Propeller 80 column display. As per an earlier post, my peripherals board is curren...

Martin, Was "Hitchhikers Guide to the Galaxy" a Z-Machine game? Not every adventure game was. Only 64K of RAM. OK, that means first trying to improve the disk caching. I have some ideas on that. Then see whether the implementation of the Z-Machine emulation can be improved. I was not sure ...

But does anyone want them? Zork_2.png The Z-Machine is a virtual computer for running text adventure games stored in "story files". Originally developed by Infocom in 1969 for their games, the Z-Machine is considered to be one of the first uses of virtual memory. Both the Z-Machine specifi...