Search found 344 matches

by Nasta
Sun Apr 28, 2019 12:41 am
Forum: Hardware
Topic: ULTRA GOLD CARD
Replies: 24
Views: 3818

Re: ULTRA GOLD CARD

As the author of said vaporware, I can only agree. When I did Aurora I hoped it would get the QL out of it's old case but no such luck... If the announcement was about a variant of the GoldFire, then why does it say "Miracle Systems" and not "Nasta"? Are you sure this was not so...
by Nasta
Sun Apr 28, 2019 12:01 am
Forum: Software & Programming
Topic: SCREEN1 = SYSVAR @ JSROM
Replies: 90
Views: 14701

Re: SCREEN1 = SYSVAR @ JSROM

Why not check out Minerva? It's already designed to work with 2 screens and in fact the con driver linkage block can be modified to generate graphics in the second screen - in fact, in theory, anywhere in memory. It's fairly easy to look at the two screens as a larger 512 x 512 bitmap and then use i...
by Nasta
Sat Apr 27, 2019 11:23 am
Forum: Hardware
Topic: ULTRA GOLD CARD
Replies: 24
Views: 3818

Re: ULTRA GOLD CARD

Seems like fitting the QL case is so important that even vaporware appears more gigantic than a machine that actually shipped. ;) I already noticed that in the old days... everything of importance needed to fit the QL case... And people were then tinkering to move their stuff outside the QL case, b...
by Nasta
Sat Apr 27, 2019 11:19 am
Forum: Software & Programming
Topic: How to reliably detect USER or SUPERVISOR mode across CPUs
Replies: 12
Views: 1613

Re: How to reliably detect USER or SUPERVISOR mode across CPUs

Dave wrote:How might detecting this tie in with detecting and enabling caches on the 68000, 68020, 68030 and 68060?


Enabling cache on a 68000 is REALLY hard.
by Nasta
Fri Apr 26, 2019 2:31 pm
Forum: Hardware
Topic: ULTRA GOLD CARD
Replies: 24
Views: 3818

Re: ULTRA GOLD CARD

That was actually the specification for a card which I was designing called GoldFire which was never finished for a variety of reasons I won't go into here. It also had a an option for an ethernet and audio controller chip, all derived from PC tech of the day. The reason for the name was that the de...
by Nasta
Tue Apr 16, 2019 7:24 pm
Forum: Hardware
Topic: Optimal Flatscreen monitors for QL and Q68
Replies: 24
Views: 3516

Re: Optimal Flatscreen monitors for QL and Q68

That's a rather complex discussion. The QL uses a 'fake progressive' timing close to the PAL spec with some liberties which never the less work fine on PAL compatible TVs and monitors. This format has 640 pixels per line, and 312 lines, which includes all invisible portions of the scan. Each line ta...
by Nasta
Tue Apr 16, 2019 6:18 pm
Forum: Hardware
Topic: WD1772 vs DP8473V
Replies: 8
Views: 1360

Re: WD1772 vs DP8473V

So far we can assume the old ULAs at $18000..$180FF and Qimi (original, not the one on the SQB) at $1BF00..$1BFFF. The rest is more or less up for grabs. One entry which I would add to this, is the entire first 4k of that area. There is a hidden agenda behind that one :P Curiosity raised :-) Someth...
by Nasta
Sat Apr 13, 2019 12:18 pm
Forum: Hardware
Topic: Issue 8 discussions...
Replies: 147
Views: 24746

Re: Issue 8 discussions...

It never has to contend for memory with the CPU as they are on separate and isolated buses, on either side of dual port RAM that allows both sides to access the same address simultaneously without conflict. This is the problem I meant. When the CPU is writing, while by chance the asynchronously clo...
by Nasta
Sat Apr 13, 2019 11:13 am
Forum: Hardware
Topic: Floating a thought to understand the issues...
Replies: 29
Views: 3603

Re: Floating a thought to understand the issues...

Some improvement in Interrupt handling can be done with the 'status affects vector' mechanism that z80 I/O and some of the 68K peripherals use. ...Little or no need to interrogate an ISR to find out what caused the interrupt. The down side is that almost all of the user vector space is clobbered by...
by Nasta
Thu Apr 11, 2019 3:12 pm
Forum: Hardware
Topic: Floating a thought to understand the issues...
Replies: 29
Views: 3603

Re: Floating a thought to understand the issues...

Let me backtrack here a bit, re 'blocking' and 'non-blocking' tasks. Once a second CPU is in the picture to handle IO, almost all tasks become 'non-blocking' in 'Dave-speak' :) The reason some things take over the entire machine are mostly historic. The underlying principle, though, is always presen...