Hi all, the german Engeneer Tillman Reh has build an Zilog Z280 SBC card with Eurocard Bus connector: http://oldcomputers.dyndns.org/public/pub/rechner/zilog/z280/index.html The Software is open and Tillman allows the PCB to be reproduced from his original Gerber files on request.
Unfortunately some parts for those cards are almost unobtanium in the meantime, the Zigzag DRAMs, the COM8117 Uart, the LT1134 Driver chip and also the SMC FD37C65CLJP FDC are difficult to source. I have two such cards and I got all the necessary parts, but I have friends that are also interested in such a card to run CP/M 3 or UZI280 on that Z280 (The Z800!) 16 Bit CPU. There are many other FDCs that should be compatible, the WD37C65 for example. This was used in many PC related Floppy controllers..but they are in fact not compatible. The use of the SMC37C65CLJ P seems to be necesary for this board, for reasons that are unclear. While copying data to the disc there happens a timeout on the earlier FDC varaints, I have read somewhere that reading the status register gives unexpected results, they have tried to fix this already in the 90ies by inserting some delays, w/o success. Has someone here Errata Sheets for those SMC FD37C65B (not working) and FDC37C65C (working) variants of that FDC Chip, so that one can see what they may have changed between the releases? Here are some part of the BIOS: ; I/O-Page mu~ bereits auf BOARDP gesetzt sein. Ver{ndert ABHL. FdcCom:: if loader ld hl,CList else ld hl,(CmdAdr) ; Zeiger auf Befehlsliste endif FdcCo1::in a,(FdcSta) ; (Einsprung mit Zeiger in HL) rla jr nc,FdcCo1 ; warten bis FDC-RQM (Request for Master) rla jr c,FdcErr ; bei falscher Datenrichtung: DIO-Error nop nop nop ld a,(hl) out (FdcDat),a ; Befehls/Datenbyte an FDC ausgeben inc hl ; Zeiger auf naechstes Byte djnz FdcCo1 ; alle Befehlsbytes ausgeben ret ; DIO-Error (Datenrichtungsfehler im FDC) : Stoppen des Systems ;*** evtl. Fehler korrigieren und weiterarbeiten? ; (Ist Fehler ueberhaupt korrigierbar?) FdcErr: ld hl,DioMsg call PMsg ; "DIO-Error" ausgeben di halt ; sicherheitshalber nicht weiter arbeiten It seems that the FDC Status register requests a data transfer in the wrong direction on the B-Release Chips... It is this "DIO-Error" that happens after a few write operations, but formating the disk is possible. Kind Regards, Holm -- Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe, Goethestrasse 15, 09569 Oederan, USt-Id: DE253710583 i...@tsht.de Fax +49 37292 709779 Tel +49 37292 709778 Mobil: 0172 8790 741