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MZ-80A RFS Board / MZ-700 tranzputer Board

Posted: Sun Apr 18, 2021 9:38 am
by psmart
I've got to a point on my projects where I feel other enthusiasts may be able to make use of them, namely:

Rom Filing System Upgrade board - Adds ROM / RAM storage and SD Card along with an upgraded monitor which runs alongside the original SA-1510 Monitor. I've also updated BASIC SA-1510 and NASCOM Microsoft BASIC to run on the Sharp with SD card access. More info: - I made up 4 of these boards, one is already spoken for so 3 to go.

TranZPUter FPGA upgrade board - Adds 40/80 column colour VGA output (+ other video modes such as the MZ-80B Pixel graphics 640x200), faster CPU upto 24MHz etc. More info: - I made up 7 of these boards, 4 are already cited in machines so 3 to go.

The price of these boards is not cheap, not because of profit as I'm selling at component cost price to me not including labour etc, just the parts are expensive (ie. the FPGA on the tranzputer, if bought from Mouser Electronics, will set you back circa GBP180 alone - I bought a bankrupt stock so got a batch of them at approx GBP30 each, the PCB's being filled via and small land size also cost me 320 for 10!!!). If these are of interest to anyone please contact me direct as the ones on Ebay are just to test the water to see if I'm flogging a dead horse, ie. no interest in Sharp MZ upgrades or price to build too high!

I can hopefully direct my time to the FPGA Emulator on MiSTer now as a lot of knowledge was gained making the above boards which needs to go into the emulator. I will shortly get an MZ-2000, the missing link on the emulator, giving a good reason to finish it.

Re: MZ-80A RFS Board / MZ-700 tranzputer Board

Posted: Sun Apr 18, 2021 10:19 am
by hlide
I would be interested in MZ-80A upgrade board with a 40/80 columns card. Few years ago, I acquired an ill-working MZ-80A with 40/80 modding but I may restore it in its original hardware as it is not stable.

MZ-2500 in the FPGA emulator will be the summum as I think it is the last of the B series.

Re: MZ-80A RFS Board / MZ-700 tranzputer Board

Posted: Sun Apr 18, 2021 11:01 am
by psmart
Thank-you, will put one aside. The video card has a bug on the external display output I think arising from the Sharp MZ Gate Arrays which I only found out whilst readying a board for a guy and made some final tests.

The issue is in the external Vertical Sync and Horizontal Sync separation, the separator circuit originates from Oh! Ishi’s most excellent museum site and separate’s as expected. Unfortunately, and it may just be my MZ-80A motherboard, there is a glitch on the Horizontal Sync which stops some digital monitors from recognising the signal. The attachment below you can see the issue, Yellow is Horizontal Sync, Blue is Vertical Sync, Purple is Horizontal Blanking and Green is Composite Sync. Just before Vertical Sync (Blue) goes active (low) the Horizontal Sync mimics the Composite and the Composite signal itself doesn’t look right, it comes from the mainboard, it shouldn’t have two pulses. The Horizontal Sync should be uniform, Ie a pulse every 64uS. Will figure it out, eventually, but it may need additional parts soldering onto the card to resolve. I looked at using a diode OR gate between the output of the multivibrator and the input to the XOR gate, increasing the timing on the LS123 multivibrator to ~44uS but that wasn't successful.

So given the above issue, your welcome to a video card at no cost and I can post you the correction when I devise one. One note on the video card, you need to de-solder and socket IC 8 on the MZ-80A mainboard in order to use it (instructions: ... tion-notes ).

I’m still waiting for my MZ-2500, have gathered and read documentation so if I have the energy will look at adding the MZ2500 as it will be a challenge, albeit will need to separate the logic which I think you suggested a long time ago, into the K series and B series. First challenge is the MZ-2000 – I love the looks of this machine so it may become my favourite (the MZ-80A has always been my favourite till now!).
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