Search found 243 matches

by Bill B
25 Jun 2020 20:24
Forum: OFF TOPIC
Topic: Another Home-Brew - Z180
Replies: 64
Views: 9783

Re: Another Home-Brew - Z180

The Z180 I am using is rated at 33MHz. I will probably get 10MHz and 16MHz oscillator modules.
by Bill B
25 Jun 2020 16:04
Forum: OFF TOPIC
Topic: Another Home-Brew - Z180
Replies: 64
Views: 9783

Re: Another Home-Brew - Z180

It lives :) 20200625_142727.jpg 20200625_142759.jpg Some very minimal firmware (source attached): Configures one of the serial ports for input and output Performs some basic memory tests Echoes text typed in Uploads and executes hex files This last feature will allow me to do further software develo...
by Bill B
20 Jun 2020 11:21
Forum: OFF TOPIC
Topic: Another Home-Brew - Z180
Replies: 64
Views: 9783

Re: Another Home-Brew - Z180

Sheesh that's a lot of work to get the CPLS programmed! Since the whole project is just a pass-time anyway, what does it matter :roll: Besides, I learn stuff along the way. I once discovered a "T" rating for projects: T0: A project that you can complete with existing tools. T1: A project where you ...
by Bill B
17 Jun 2020 14:22
Forum: OFF TOPIC
Topic: Another Home-Brew - Z180
Replies: 64
Views: 9783

Re: Another Home-Brew - Z180

Forward progress at last :o I (eventually) managed to turn a Teensy 3.5 into a "USB Blaster" clone. Details here . Breadboard testing suggests that the resulting programmed EPM7032S behaves as expected. Since, as part of my work on CFX video, I built a Raspberry Pi powered programmer for Flash ROM c...
by Bill B
01 Jun 2020 18:35
Forum: OFF TOPIC
Topic: Another Home-Brew - Z180
Replies: 64
Views: 9783

Re: Another Home-Brew - Z180

I do have some old PCs with parallel ports, but I doubt any of them are up to running Quartus. One option would be to try and purchase a serial / parallel card for the (reasonably) modern PC I am running Quartus on. Slightly more interesting would be to try and run Quartus within some form of VM, an...
by Bill B
31 May 2020 14:49
Forum: OFF TOPIC
Topic: Another Home-Brew - Z180
Replies: 64
Views: 9783

Re: Another Home-Brew - Z180

This project has not been abandoned. it is just taking longer than expected. It got put on the back burner while I played with CFX-II video, but I am now, sort of, back on it. The problem is still that of programming the CPLD. Having had one programmer that I purchased fail, I am disinclined to buy ...
by Bill B
07 May 2020 08:52
Forum: OFF TOPIC
Topic: Printer replacement
Replies: 6
Views: 622

Re: Printer replacement

ZX81 / Spectrum printer is certainly not a Centronics interface. If I remember correctly it a simple raster output. Back in the day I created a fairly simple interface (no Microcontroller) that emulated the Sinclair printer and printed on a till-roll printer. It did rely on the particular printer I ...
by Bill B
06 May 2020 22:32
Forum: OFF TOPIC
Topic: Printer replacement
Replies: 6
Views: 622

Re: Printer replacement

The hardware is providing an interface to a Raspberry Pi. On the RPi you have all the Linux printer support. The software part is not that difficult. I have written something similar, but on a Windows PC. My father had a number of programs that he had written in GW-BASIC. Now GW-BASIC is convinced t...
by Bill B
05 May 2020 10:49
Forum: OFF TOPIC
Topic: Printer replacement
Replies: 6
Views: 622

Printer replacement

I ran across a reference to this in the Raspberry Pi forums. It might be of interest to anyone without a working Centronics printer.

Probably not too difficult for a hardware hacker to knock-up their own version.
by Bill B
01 May 2020 17:48
Forum: NEW HARDWARE
Topic: SPX - Large capacity, read only, "disc" system
Replies: 2
Views: 671

Re: SPX - Large capacity, read only, "disc" system

If the chip is supplying 4 bits of data, would it be better to have two chips in parallel to supply 8 bits? Would the speed improvement in not having to repack the data be worth the cost of the extra chip?