Search found 304 matches

by Bill B
11 Apr 2021 18:58
Forum: SOFTWARE
Topic: Question #2: EXEROM and tape loading
Replies: 29
Views: 470

Re: Question #2: EXEROM and tape loading

Also, although the ROMs are cramped, they also provide a lot of flexibility. I count 12 places in the system variables where it is possible to insert code to modify or extend the behaviour of BASIC.

How many other machines of that era provide that level of flexibility?
by Bill B
08 Apr 2021 18:55
Forum: SOFTWARE
Topic: Question #2: EXEROM and tape loading
Replies: 29
Views: 470

Re: Question #2: EXEROM and tape loading

Don't know. Probably would not work.

Could use ROM 6 instead, but that would need some extra logic to decode the ROM 6 signal.
by Bill B
08 Apr 2021 16:58
Forum: SOFTWARE
Topic: Question #2: EXEROM and tape loading
Replies: 29
Views: 470

Re: Question #2: EXEROM and tape loading

One option might be an external ROM 7 which defined some new USER commands, perhaps including improved tape handling. But then if you are adding additional hardware anyway, might as well add CFX-I, -II or Rememorizer. I suppose it might be possible to add some improved tape handling to the CFX ROM. ...
by Bill B
04 Apr 2021 09:03
Forum: GENERAL DISCUSSIONS
Topic: Keyboard layout
Replies: 14
Views: 356

Re: Keyboard layout

If you look at Dave's site here you will find at the bottom of the page a download link for "kbdfixup.zip". This is a small COM program for modifying the keyboard tables. It is intended to add support for the phantom keys used by the PC keyboard interface, however the source code is included, and it...
by Bill B
02 Apr 2021 14:02
Forum: OFF TOPIC
Topic: Another Home-Brew - Z180
Replies: 102
Views: 32843

Re: Another Home-Brew - Z180

I would be interested to know where you purchased that from.

I think I found it:
https://www.amazon.co.uk/TeckNet-Mechan ... B010IIKHBK
by Bill B
02 Apr 2021 13:58
Forum: GENERAL DISCUSSIONS
Topic: Keyboard layout
Replies: 14
Views: 356

Re: Keyboard layout

Memotech actually missed a trick here. The 8 x 10 keyboard matrix has three positions without any keys. By inserting or omitting wire links (or better diodes) in the position of those missing keys, they could have identified up to eight different keyboard layouts. And because the links would be on t...
by Bill B
02 Apr 2021 09:08
Forum: GENERAL DISCUSSIONS
Topic: Keyboard layout
Replies: 14
Views: 356

Re: Keyboard layout

Bits 2 & 3 of input port 0x06 are supposed to return a Country Code, one of four values. However, I am not sure exactly how these bits are set. The circuit diagram in the user manual shows a switch (SWA). However I don't think there is a switch, probably just some links. Also, the connections for th...
by Bill B
30 Mar 2021 22:38
Forum: OFF TOPIC
Topic: Another Home-Brew - Z180
Replies: 102
Views: 32843

Re: Another Home-Brew - Z180

I should stick to software. Or at least learn not to be impatient and triple check everything :oops: I managed to mirror image the footprint of the PS/2 socket. Once I realised what I had done, correcting the layout and remaking the board did not take too long. Unfortunately, the reverse power appli...
by Bill B
27 Mar 2021 12:37
Forum: OFF TOPIC
Topic: Another Home-Brew - Z180
Replies: 102
Views: 32843

Re: Another Home-Brew - Z180

Yes, but then the circuit is very simple. Single sided boards are certainly easier to make. As you say, three jumpers. Two for ground. One of these may be unnecessary, but the ground plane goes all round the board to get from one end of the link to the other. The third is for +5V. I have seen commen...
by Bill B
26 Mar 2021 18:14
Forum: OFF TOPIC
Topic: Another Home-Brew - Z180
Replies: 102
Views: 32843

Re: Another Home-Brew - Z180

20210326_150133.jpg Serial Interface board for my Z180 computer. It has: MAX232 to provide RS232 levels for five wire serial (Tx, Rx, RTS, CTS, Gnd) for Z180 serial port 0. PIC 16F627 to convert keyboard PS/2 data to TTL serial for Z180 serial port 1. The PIC chip can supply keyboard data in three ...