MZ-80b FI/O to HxC Cable

arnuphis
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Re: MZ-80b FI/O to HxC Cable

Post by arnuphis »

Tested all connections. Still no joy. The Sharp seeks the Gotek and that's it. Almost as if its waiting for a response that is not coming. Out of ideas at this point.
psmart
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Re: MZ-80b FI/O to HxC Cable

Post by psmart »

Which FD card do you have, the MZ-80AFI, MZ-80FIO, MZ-1E05? The official one for the MZ-80B should be the MZ-80FIO and looking at it's manual there is nothing special about it, ie: https://original.sharpmz.org/mz-80b/download/sm80fd.pdf - on the other hand if it is the MZ-80AFI then this uses an inverted data controller IC which gave me trouble when trying to get CP/M running on the MZ-80A and processing it's disks.

Have you had any disk work with the MZ-80B and this controller? Just wondering on it's functional state.

The SFD800 board should take about 2 weeks to arrive and probably about a week for me to make the first board and test it, I plan to use a GAL16V8 instead of the PAL12L6 as the former are reprogrammable and I bought 10 last night (reused but tested, UK supplier). I could most certainly provide you with the board/GAL/WD1773 at cost (GAL=GBP10 for 10, WD1773=GBP30 for 5 - so GBP1 for the GAL, GBP6 for the WD1773, nothing for the PCB), the other components I plan to use 74HCT parts but will advise a more detailed parts list once I've built the first board, I intend to use sockets so I can try out different parts from my bin. I'll also generate a BOM with part price and supplier.

In terms of the SFD800 it is a near replication, parts location, size etc are all done using a micrometer on the original board, power distribution the same as the original board (but copper filled at the end), routing is slightly different using Kicad techniques rather than the hand drawn original.
Sharp MZ/X Series Projects and FPGA Emulator
engineers@work : https://eaw.app/sharpmz-series/
arnuphis
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Joined: Fri Jul 31, 2020 4:18 pm

Re: MZ-80b FI/O to HxC Cable

Post by arnuphis »

Great. Let me know some prices when you get it all together.

As for the card it is a MZ080FIO pulled from a working machine. I don't have the floppy drives or original cable. I am loathe to think the card is the issue. Maybe once the HxC arrives we can see for sure If I cannot get that working then obviously something else is amiss. I still think its a cabling issue. The Sharp boots up and seeks the drive. The menu appears. I choose F and then drive number and it seeks again. So its responding and trying at least. I wonder if it is something to do with the ready signal. I posted the pinouts over on the HxC forum to see if they can suggest anything.
arnuphis
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Re: MZ-80b FI/O to HxC Cable

Post by arnuphis »

Had a couple of suggestions over on that forum but still no dice. Still waiting on my HxC to arrive. Fingers crossed the Gotek is the issue.
psmart
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Re: MZ-80b FI/O to HxC Cable

Post by psmart »

Hopefully the HxC will solve the immediate issue but the Gotek should work, just getting the cable right (easier said than done!).

I've generated a new GAL configuration file for the SFD800 (below) and tested it on the SFD800 on my MZ-800 (need to verify on the 80B) and all works fine, so just a matter of waiting for the PCB's/WD1773's.

WinCUPL configuration file for a GAL16V8B device to replace the MMI PAL12L6 on the SFD800 board:

Name SFD800 ;
PartNo PAL12L6 ;
Date 20/05/2021 ;
Revision 01 ;
Designer Philip Smart ;
Company engineers@work ;
Assembly SFD800 ;
Location ;
Device g16v8a;

/* *************** INPUT PINS *********************/
PIN 1 = A0 ; /* Address bus A0 */
PIN 2 = A1 ; /* A1 */
PIN 3 = A2 ; /* A2 */
PIN 4 = A3 ; /* A3 */
PIN 6 = A4 ; /* A4 */
PIN 7 = A5 ; /* A5 */
PIN 8 = A6 ; /* A6 */
PIN 9 = A7 ; /* A7 */
PIN 19 = IORQn ; /* Z80 IORQ active low */
PIN 11 = WRn ; /* Z80 WR active low */
PIN 12 = RDn ; /* Z80 RD active low */
PIN 5 = RESET ; /* System Reset active high */

/* *************** OUTPUT PINS *********************/
PIN 13 = BUSn ; /* BUS direction, low = read into Z80, high = write to FD IC's */
PIN 18 = FDCn ; /* WD1773 Chip Select active low I/O - Address 0xD8 .. 0xDB */
PIN 14 = DRIVEn ; /* Disk Drive Select active low - Address 0xDC */
PIN 17 = DDENn ; /* Drive Density select active low - Address 0xDE */
PIN 15 = RESn ; /* Peripheral Reset active low */
PIN 16 = SIDEn ; /* Disk Head Select active low - Address 0xDD */

/* Decoder equations. */
FIELD ADDR = [A7..A0];
WD1773SEL = !IORQn & ADDR:[D8..DB];
SIDESEL = !IORQn & !WRn & ADDR:[DD..DD];
DRIVESEL = !IORQn & !WRn & ADDR:[DC..DC];
DDENSEL = !IORQn & !WRn & ADDR:[DE..DE];
BUSREAD = !IORQn & !RDn & ADDR:[D8..DE];

/* Assign output pins based on equations. */
BUSn = !BUSREAD;
RESn = !RESET;
FDCn = !WD1773SEL;
SIDEn = !SIDESEL;
DRIVEn = !DRIVESEL;
DDENn = !DDENSEL;
Sharp MZ/X Series Projects and FPGA Emulator
engineers@work : https://eaw.app/sharpmz-series/
arnuphis
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Joined: Fri Jul 31, 2020 4:18 pm

Re: MZ-80b FI/O to HxC Cable

Post by arnuphis »

Looking good. You may actually get this card up and running before I get my HxC
psmart
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Re: MZ-80b FI/O to HxC Cable

Post by psmart »

Tested the SFD800 on the MZ-80B today using the HxC, an ASUS twisted floppy cable, the disk images from original.sharpmz.org and the new GAL and as can be seen, everything works, CP/M + DISK BASIC SB-6511. If you dont have joy with your HxC then the Floppy Disk Interface card will be the culprit.
MZB - 1.png
MZB - 1.png (518.58 KiB) Viewed 620 times
MZB - 2.png
MZB - 2.png (464.05 KiB) Viewed 620 times
MZB - 3.png
MZB - 3.png (447 KiB) Viewed 620 times
MZB - 4.png
MZB - 4.png (383.96 KiB) Viewed 620 times
Sharp MZ/X Series Projects and FPGA Emulator
engineers@work : https://eaw.app/sharpmz-series/
arnuphis
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Re: MZ-80b FI/O to HxC Cable

Post by arnuphis »

Excellent work! I think my HxC will be here this weekend. I am interested in getting one of these cards regardless.
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dat-alex
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Re: MZ-80b FI/O to HxC Cable

Post by dat-alex »

@psmart: !!Excellent work!! (You catch me up with FDC800 replica pcb I was working in the same approach ,too!) Started designing the pcb but I decided to replace digital logic with CPLD and keep only WD1773 and inverter. I hope to manage to run CP/M on my beloved 80b soon! Maybe future approach would be to replace WD1773 with FPGA . Ι know there are (maybe 80b compatible) mz800 sdcard solutions out there, but the real challenge for me is that I want to use original floppy disks to run CP/M. :)
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psmart
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Re: MZ-80b FI/O to HxC Cable

Post by psmart »

This is just a test of the GAL (to replace the PAL) in the original board. The new boards are almost the same (different routing and copper fills) so I dont expect any gotcha's, made several tests to verify the hand drawn schematic against the physical card. Just waiting for the parts to arrive, hopefully this week.

As mentioned to arnuphis/alo2004, if you want a PCB/GAL then I can send one at cost, the PCB's were US$63 for 10 and the GAL's were GBP1 each. The SFD800 may be good reference to complete the FPGA design.

I'm looking for a good VHDL WD1773 reference design for my Sharp MZ Emulator, have found Verilog compatibles which I may translate if a vhdl version isnt forthcoming.

ps) The Lotharek HxC may be a floppy emulator, but it makes some of the right noises :)
Sharp MZ/X Series Projects and FPGA Emulator
engineers@work : https://eaw.app/sharpmz-series/
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