Tiny SC/MP system !!! - Page 7 - UK Vintage Radio Repair and Restoration Discussion Forum

Realtime · 6th Mar 2024, 11:11 pm

Very nice. So the 4K ROM on #111 is write protected NVRAM, but can be writable for OS updates if the jumper is moved to its other position. I assume the SCIOS is permanently write protected.

With all that ram available, I think it’s time to resurrect MK14 monster maze

Mark1960 · 6th Mar 2024, 11:32 pm

Would the GAL be able to select a fixed page when nENIN is held high? This might avoid the 3k page limit mentioned in #111.

Phil__G · 14th Mar 2024, 11:03 am

Quote:

Originally Posted by coolsnaz2

Quote:

Originally Posted by Phil__G

16v8 does tristate Ian

... still learning what the GAL can do.

actually the 22v10 can also do tristate but you have to declare pin 13 as /oe

coolsnaz2 · 15th Apr 2024, 8:23 pm

Another update on my MK14-NV board.

As Mark suggested I have intercepted the NRDS and NWDS going between the daughter board and the main MK14 board, this has allowed me to remove the need for the fly leads.

And as Phil suggested I am using the tristate feature of the GAL22V10 to generate NRDS and NWDS for the MK14 board.

I am currently waiting for a second batch of boards to be delivered with the modifications included, but have produced a video showing the board in action.

https://www.youtube.com/watch?v=S8MWvlWic5o

SiriusHardware · 16th Apr 2024, 12:32 am

Good video, for several reasons

-Demonstrates a level of usability that we could only have dreamed of in the late 1970s

-Short demos of many of the high-end MK14 software titles which have been created recently

-Showcases PiView, especially its colour capability.

Keep up the good work!

SiriusHardware · 16th Apr 2024, 8:46 am

Also, first time I've seen one of the cherry-switch-equipped "issue VII" PCBs in use.

ortek_service · 16th Apr 2024, 10:09 am

Thanks for the update on you now having this working OK on a (modified) original board.

I'd be interested in the schematic & GAL22V10 changes, to try on mine as I still need to connect it to an MK14
- after being busy looking into upgrading the MGH8060 to all the capabilities of the MGH8060GAL with its GAL22V10 (but should be able to do virtually all that does on a GAL18V10 as Tx Inverter is external to it on the MGH8060, so freeing-up some more I/O pins).

I do need to re-write the ROM-images in the DS1845Y, as whilst checking these, I discovered the Dataman 48Pro(+) / the last version (v3.56) of the control software to support it has a rather major bug in that it can't often (read?) / write even the first line of hex correctly with odd interaction between the initial bytes. But it does seem to work if all bytes have the same value So I image the cut-down MemPro version will also be affected.
Whereas the original Dataman48(LV/XP) (as well as TL866) does seem to work OK.

6th Mar 2024, 11:11 pm	#121
Realtime Hexode Join Date: Jan 2021 Location: Ashford, Kent, UK Posts: 320	Re: Tiny SC/MP system !!! Very nice. So the 4K ROM on #111 is write protected NVRAM, but can be writable for OS updates if the jumper is moved to its other position. I assume the SCIOS is permanently write protected. With all that ram available, I think it’s time to resurrect MK14 monster maze

6th Mar 2024, 11:32 pm	#122
Mark1960 Octode Join Date: Mar 2020 Location: Kitchener, Ontario, Canada Posts: 1,298	Re: Tiny SC/MP system !!! Would the GAL be able to select a fixed page when nENIN is held high? This might avoid the 3k page limit mentioned in #111.

15th Apr 2024, 8:23 pm	#124
coolsnaz2 Tetrode Join Date: Aug 2020 Location: Wallington, Greater London, UK. Posts: 87	Re: Tiny SC/MP system !!! Another update on my MK14-NV board. As Mark suggested I have intercepted the NRDS and NWDS going between the daughter board and the main MK14 board, this has allowed me to remove the need for the fly leads. And as Phil suggested I am using the tristate feature of the GAL22V10 to generate NRDS and NWDS for the MK14 board. I am currently waiting for a second batch of boards to be delivered with the modifications included, but have produced a video showing the board in action. https://www.youtube.com/watch?v=S8MWvlWic5o

16th Apr 2024, 12:32 am	#125
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,598	Re: Tiny SC/MP system !!! Good video, for several reasons -Demonstrates a level of usability that we could only have dreamed of in the late 1970s -Short demos of many of the high-end MK14 software titles which have been created recently -Showcases PiView, especially its colour capability. Keep up the good work!

16th Apr 2024, 8:46 am	#126
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,598	Re: Tiny SC/MP system !!! Also, first time I've seen one of the cherry-switch-equipped "issue VII" PCBs in use.

16th Apr 2024, 10:09 am	#127
ortek_service Octode Join Date: May 2018 Location: Northampton, Northamptonshire, UK. Posts: 1,444	Re: Tiny SC/MP system !!! Thanks for the update on you now having this working OK on a (modified) original board. I'd be interested in the schematic & GAL22V10 changes, to try on mine as I still need to connect it to an MK14 - after being busy looking into upgrading the MGH8060 to all the capabilities of the MGH8060GAL with its GAL22V10 (but should be able to do virtually all that does on a GAL18V10 as Tx Inverter is external to it on the MGH8060, so freeing-up some more I/O pins). I do need to re-write the ROM-images in the DS1845Y, as whilst checking these, I discovered the Dataman 48Pro(+) / the last version (v3.56) of the control software to support it has a rather major bug in that it can't often (read?) / write even the first line of hex correctly with odd interaction between the initial bytes. But it does seem to work if all bytes have the same value So I image the cut-down MemPro version will also be affected. Whereas the original Dataman48(LV/XP) (as well as TL866) does seem to work OK.