Search found 1163 matches

by stephen_usher
Wed Jan 27, 2021 10:20 pm
Forum: 8 BIT CORNER
Topic: Bah! My ZX81 gone faulty! :-(
Replies: 0
Views: 25

Bah! My ZX81 gone faulty! :-(

I brought it down from the loft to give it a check-out before the 40th anniversary in March, plugged it in and switched it on without the RAM pack and it worked for a few seconds and then the output signal disappeared. Swapping the vLA81 ULA replacement out and putting the original ULA at least got ...
by stephen_usher
Wed Jan 27, 2021 9:58 am
Forum: SOFTWARE
Topic: Spectre GCR on the TT.
Replies: 4
Views: 114

Re: Spectre GCR on the TT.

I'm afraid I don't know. I've never tried using the emulator on any platform.

It wouldn't really help me in this case as it wouldn't be able to read Spectre partitions or use the GCR hardware.
by stephen_usher
Wed Jan 27, 2021 9:54 am
Forum: INTRODUCE YOURSELF
Topic: Hi!
Replies: 5
Views: 58

Re: Hi!

:welcomewave:
by stephen_usher
Tue Jan 26, 2021 9:50 pm
Forum: SOFTWARE
Topic: Spectre GCR on the TT.
Replies: 4
Views: 114

Re: Spectre GCR on the TT.

Thanks. I know that it has to page the two halves of the ROMs as the ROMs are 128KB but there's only 64KB visible at any one time. I'm guessing that it must make a workable copy in RAM.
by stephen_usher
Tue Jan 26, 2021 6:49 pm
Forum: SOFTWARE
Topic: Spectre GCR on the TT.
Replies: 4
Views: 114

Spectre GCR on the TT.

I wonder if any of you know whether it's the Spectre GCR application or the emulated Mac produces the *BOOP* when you start the emulator? I'm yet again trying to get Spectre GCR to work on my TT and it would be useful to know if the Mac ROM code is actually starting or not. The symptoms are that whe...
by stephen_usher
Mon Jan 25, 2021 9:14 pm
Forum: EXXOS WEBSTORE INFORMATION
Topic: VAT charges to EU states
Replies: 36
Views: 1350

Re: VAT charges to EU states

Ps: for UK shops they recommend that you clearly specify on the invoice that your products are made in UK The problem here is that the parts which make up the Exxos equipment aren't made in the UK, they're sourced from around the World, and there are feindishly complex rules about how much value ha...
by stephen_usher
Mon Jan 25, 2021 12:07 pm
Forum: RAM UPGRADES
Topic: RAM chips randomly failing
Replies: 2
Views: 52

Re: RAM chips randomly failing

Or they're manufactured by MT.
by stephen_usher
Mon Jan 25, 2021 8:28 am
Forum: HARDWARE ISSUES
Topic: Issue writing data on floppy (Write protected)
Replies: 20
Views: 744

Re: Issue writing data on floppy (Write protected)

Have you been testing the floppy with the UltraSATAN connected? If so then disconnect it and try again. I had similar issues on my machine with the TF536. The UltraSATAN's design is a bit iffy and pulls way too much current on the data lines, which can upset the DMA chip. The issue got worse over ti...
by stephen_usher
Sun Jan 24, 2021 8:49 pm
Forum: SOFTWARE
Topic: Sozobon C's a bit broken isn't it?
Replies: 12
Views: 167

Re: Sozobon C's a bit broken isn't it?

The alternative to testing the whether the address is below the end of the cartridge port address range is to use a counter and test if that's less than the total, e.g.

Code: Select all

....
	unsigned long i;
....	
	for (i = 0; i < 0x20000L ; i++)
		printf("0x%02x\t", addr++);
....
by stephen_usher
Sun Jan 24, 2021 6:40 pm
Forum: SOFTWARE
Topic: Sozobon C's a bit broken isn't it?
Replies: 12
Views: 167

Re: Sozobon C's a bit broken isn't it?

Yes, lines 8 & 9 should be:

Code: Select all

	unsigned char *addr = (unsigned char *) CARTSTART;
	unsigned char *endaddr = (unsigned char *) CARTEND;

Go to advanced search