Super Gold Card (Clone)

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Peter
Super Gold Card
Posts: 680
Joined: Sat Jan 22, 2011 8:47 am

Re: Super Gold Card (Clone)

Postby Peter » Tue Oct 23, 2018 7:22 pm

tetroid wrote:Yes, my second step - EP1810 replacement.
But still not finished.
Have some problems to convert INGOT 20 to Atlra MAX.
Original INGOT20 have errors, I try to check the JED code manually.


Impressive again! But wouldn't it be easier to design the whole logic from scratch instead of reproducing the original EP1810?

Another remark: It could make sense to solder the DRAM directly to the PCB... by Q60 VRAM experience, the sockets add more risk of contact problems, but little benefit.


stephen_usher
ROM Dongle
Posts: 37
Joined: Tue Mar 11, 2014 8:00 pm

Re: Super Gold Card (Clone)

Postby stephen_usher » Tue Nov 06, 2018 6:06 pm

Well, I ordered one and it arrived today!

Working fine (haven't tested floppies).

Thank-you Tetroid!

Image

Image


martyn_hill
Gold Card
Posts: 429
Joined: Sat Oct 25, 2014 9:53 am

Re: Super Gold Card (Clone)

Postby martyn_hill » Wed Nov 07, 2018 5:03 pm

My cloned SGC also arrived recently!

Nicely packaged and beautifully built, though no enclosed instructions - not a problem here.

Booting-up on an Iss6 QL running Minerva 1.98 (with Marcel's 'Serial IO fix') however failed for me stating that the ROM was unrecognised - and I know why - nothing to do with the SGC itself...

To differentiate my various EPROMs (I have 4 QLs now - don't ask...), I adjusted the Minerva version string from "1.98" to "1b98" before burning that EPROM.

IIRC, the SGC ROM checks the ROM version before then patching its fast RAM copy - but of course can only patch against known version IDs...

Silly me! I'll re-burn a fresh EPROM without tweaking the version ID and try again.

But it did get me wondering about ROM compatibility with SGC - namely, even with the Minerva version ID set to something SGC will actually recognise, might we hit problems with say, Marcel's IO Fixed version, due to byte-offsets changing (one additional instruction, in that case)?

I'll need to review the SGC ROM patching code to know how sensitive it will be to small ROM changes/fixes.

Thank you Tetroid (and of course the original team at Miracle)! Absolutely none of the above reflects badly on your SGC clone - just on my 'tweaked' setup :-)


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Whopper
Bent Pin Expansion Port
Posts: 75
Joined: Tue Oct 24, 2017 4:04 pm

Re: Super Gold Card (Clone)

Postby Whopper » Wed Nov 07, 2018 6:42 pm

Got mine yesterday. Haven't had a chance to plug it in yet. Soon though.

:D


You woke me for THAT!!!
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mk79
Trump Card
Posts: 216
Joined: Sun Feb 02, 2014 10:54 am

Re: Super Gold Card (Clone)

Postby mk79 » Thu Nov 08, 2018 11:31 pm

martyn_hill wrote:To differentiate my various EPROMs (I have 4 QLs now - don't ask...), I adjusted the Minerva version string from "1.98" to "1b98" before burning that EPROM.
This is only a problem because you used a lower-case letter. 1B98 would have been accepted by the SGC ROM.
But it did get me wondering about ROM compatibility with SGC - namely, even with the Minerva version ID set to something SGC will actually recognise, might we hit problems with say, Marcel's IO Fixed version, due to byte-offsets changing (one additional instruction, in that case)?
Fixed offsets are only employed for known Sinclair ROMs (and these are fixes not needed on Minerva anyway). The bulk of the patches don't use fixed ROM offsets but are guided by vectors or scan the whole ROM for specific patterns. As long as you don't fiddle with the MDV, SER or reset code you should be fine.

Interestingly the patch code supplied with SMSQ/E doesn't seem to be the original source code for the patch ROM but a disassembly. A very good disassembly at times, but only done halve-way.

Marcel


martyn_hill
Gold Card
Posts: 429
Joined: Sat Oct 25, 2014 9:53 am

Re: Super Gold Card (Clone)

Postby martyn_hill » Fri Nov 09, 2018 12:54 am

Thanks Marcel! I'll just uppercase my ROM ID then and try again :-)


martyn_hill
Gold Card
Posts: 429
Joined: Sat Oct 25, 2014 9:53 am

Re: Super Gold Card (Clone)

Postby martyn_hill » Fri Nov 09, 2018 11:21 pm

Hi Marcel and everyone...

I think I've hit something with Min1.98 (original, with Marcel's IO fix plus my own 'adjusted' copy) when running on the (cloned) SGC.

Whether this is an issue with the cloned SGC (which I doubt very much) or an incompatibility between the SGC patching mechanism (v2.49 ROM as shipped with Tetroid's lovely clone) and Minnie 1.98, I'm not sure.

I'll continue this in a fresh thread in the Hardware section of the forum and see what people think...



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