Assuming the PLCC has a through hole socket, would it be possible to
solder a pcb carrier for a more modern chip on the back of the board
using the PLCC pins that protrude through?
On 11/03/2016 22:17, Peter Graf wrote:
Am 11.03.2016 21:48, schrieb Thierry Godefroy:
On Fri, 11 Mar 2016 21:16:08 +0100, Peter Graf wrote:
Strange... I'd have expected that the problem was the video memory,
but 800x600 pixels consume less memory than 1024x512 pixels...
Yes it is strange. Has to do withe the fact that neither 800 nor 600 are
powers of two and the CPLDs are manually optimized to the last gate.
No chance to get a "larger" (i.e. with more gates) CPLD that would fit
the same socket ?... Or perhaps by using a modern and larger (in both
size and number of gates) CPLD that would piggy-back on the old CPLD
socket via a small adpater printed circuit ?...
I have considered that, but adaptors which fit into PLCC are
prohibitively expensive and hard to get.
A native 800x600 resolution would be a definitive (and probably the
best) solution to the problem, so I think it would be worth investigating
some more its feasability...
Still 800x600 would require change of all three operating systems and
several pieces of application software! Moreover, software that directly
writes into QL 512x256 would fail, like the beloved QL Chess.
I can display it without scaling here also, but it looks crazy with only
about a quarter of the screen area covered.
True, but better than a blank screen... :-P
Yup.
.../...
Well, depending on how many are "a few", this could be done with
manual wiring...
If I remember correctly, it was 6 wires.
That's definitely not a problem then: I've seen (and did) hardware mods
with more "flying" wires than this...
However, another issue with this solution could be the lack of room to
piggy-back a daughter board on the EPROM slots, especially with the 2
ISA slots occupied and a heat-sink+fan on the 68060...
It depends. Using SMD components, the board could be about as small as
the ROM socket area.
.../...
It would be another machine... Not sure you'd find a "market" for it.
I guess not, but I'm not looking for a market anyway. The fewer people
want it, the less work I have. The two things that still motivate me, is
to have fun and to keep the QL alive.
So the best thing will probably be to concentrate on the Q68. This cute
piece of hardware is in working condition for more than 8 years now,
only struggling with "soft" issues and my notorious lack of time.
Any picture/spec sheet ?
Q68 runs about QXL speed, even without the cache I am working on. Features
- Plain 68000 core, 68020 nearly complete
- 32 MB SDRAM
- PS/2 keyboard and mouse
- Two fullsize SD card interfaces
- SER
- Ethernet
- Battery buffered RTC (and yes, the battery is separate!)
- Stereo sound
- Up to 1024x768 VESA VGA, QL modes in hardware
- 8x10 cm board size, fitting existing nice case
- Single 5V power supply
I demonstrated my Q68 at the "QL is 30" show, where someone took a picture:
http://www.qlforum.co.uk/viewtopic.php?f=12&t=1087&start=10
Meanwhile I replaced the wired components you see on that picture by SMD
for machine manufacture. QDOS Classic and Minerva are running, but
issues with QL-SD driver and Pointer Environment.
All the best
Peter
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