Removal of high pin count through hole devices can be done with the proper kit
no real problem. no doubt many of the repair techs here are doing it
regularly.How ever it's not for the feint hearted or those who havent got the
kit and practiced before as such it makes for a PITA job.
John A
From: derek <de...@q40.de>
To: ql-us...@q-v-d.com
Sent: Friday, 11 March 2016, 23:22
Subject: Re: [Ql-Users] Q60 aging problems
Hi,
I would be careful desoldering a PLCC chip, the D&D Q60 was soldered correctly
under the correct soldering temperature.
I have repaired some Qbranch Q40 boards, which had issues with the over heating
of the soldering, resulting in detachment of the through hole plating.
Regards
Derek
-------- Original message --------
From: Thierry Godefroy <ql.us...@free.fr>
Date: 11/03/2016 23:03 (GMT+00:00)
To: ql-us...@q-v-d.com
Subject: Re: [Ql-Users] Q60 aging problems
On Fri, 11 Mar 2016 23:17:52 +0100, Peter Graf wrote:
> .../...
> > 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.
Well, the mod could also involve unsoldering the PLCC (correct me if
I'm wrong but IRC, it's a through-holes one) and replacing it with
pinheads, for example, that would plug into the add-on board.
> > 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
These are extremely *minor* and *easy* changes (and SMSQ/E can already
cope with 800x600 screens)...
> and several pieces of application software! Moreover, software that directly
> writes into QL 512x256 would fail, like the beloved QL Chess.
Frankly, such old pieces of software are probably best ran from emulators
if they can't cope with variable size/address display... They would also
fail to run on a QXL in (S)VGA mode or on an Aurora/SGC system too. I won't
call this an issue and I think this kind of "incompatibility" should not
limit and forbid us to get a better Q60 display...
> .../...
> > 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.
In this case, I think it's still worth a solution...
> Q68 runs about QXL speed, even without the cache I am working on.
Not bad at all.
> 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!)
:-D
> - 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.
Sounds and looks good... The small size would make it an ideal "portable"
QL...
Thierry.
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