MK3000 system

In another part of the site where I discussed the research done on the history of the Italian card Ferguson Bigboard I had included some information about the system MK3000 product in Italy since 1983 by ADE Electronics Palazzolo Milanese (Milan). In December 2012 I managed to get hold of this system. E 'consists of a board with MK83 processor Z80A, Z80A two PIO (for dual port printer, mapping i / o keyboard port, one Z80A SIO / 0 to two channels 232, one Z80A CTC for system timer and a FDC 1797 management FM / MFM drives. The card features dual 50-pin IDC connector to drive 8 "and IDC 34-pin drive 5.25". The drives are present:
- Floppy disk 5.25 "BASF AG 6106 (180 Kb, SS / DD)
- Floppy disk 5.25 "Shugart SA465 (720KB DS / DD)
Unfortunately, the hardware was not completed with the respective software CP / M, although the visual conditions of the hardware is really excellent.


The Ing. Lucky Luciano at that time (1983) worked at the CNR in Pisa ended with a commitment to long-standing problem of data entry on the IBM mainframe 370 at the time used to CNUCE of Pisa. If before it was necessary to punch cards and then read them to a machine to launch their own programs, it was now simply take them on disks 5.25 "in any format readable disc through the operating system CP / M. In fact, he bought a card configured to read in either mode SSSD that DSDD and any format of bytes / sector and sectors / track can transfer protocol BSC through the program to make turn on the mainframe. Below is a description page of the system removed from the manual of which I managed to get hold of the site CNR - ISTI in Pisa:


The above seems to now be a platitude, but I remember that in 1983, this simple operation entailed huge losses of time contrary to what happens today in which this can be done either locally on their systems that eventually with any smartphone or tablet in cloud.

Unfortunately, the system was not complete boot disk for your operating system CP / M and its utility, so after connecting to the card using a PS2 keyboard interface PS2-Parallel, you connect a TV monitor with a composite PAL analog, power supplied I proceeded with an ATX power supply to turn on the card were able to achieve the initial clear screen, the message "System Monitor 4.2" and prompt "m>". There were also many other operating firmware commands as the memory dump, etc.. I then made ​​a few more tests to check how we can put it in terms of loading an operating system CP / M.

I was not certain, however, that by directly connecting the 3.5 "drives directly to the IDC connector 34-pin card MK83, they could function properly. At a minimum we would want to change the standard setting in DS1 DS0, but my experience tells me that the connector of a drive 3.5 "is not immediately compatible with the connector of a drive by 5.25". To avoid dedicate to solve this problem, I decided to skip it catering to disconnect an adapter to drive I had homebuilt in January 2012 and is working perfectly with my MK82 The outline is as follows:


In it, the 50-pin IDC connector is directly connected to the IDC connector 50-pin connector on board MK82, while the connectors A, B and C are normal IDC 34-pin on which you can insert a classic flat cable to drive 3, 5 "or 5.25". D connector you can connect a flat cable to connect an external drive from 8 ". The main motivation for realizing a connection of this type is inherent in the fact that the 3.5 "drives are not directly interfaced sull'IDC the MK82 management Ready signal and because each drive expects the drive select Signal on your pin 12 while the MK83 the sngoli signals stood at different pin connector IDC 50pin (A = 26, B = 28, C = 30 and D = 32).

With this background, I have dedicated myself to try to figure out how to load an operating system CP / M.

There is to say that the contents of the Eprom (2716) of the MK83, as for the card Ferguson BigBoard 1 (= MK82), is, at the time of ignition, automatically copied to DRAM but, while in Ferguson BigBoard 1 (or MK82) is positioned at F000H, the MK83 is placed at the address F800H. Therefore it is not possible to load the card MK83 the same operating system CP / M of the MK82.

But I remembered that, c irca a year ago, I got to be contacted by a person of Modena which had an identical sheet MK83 used to deal with your knitting machine. Looking at the photos you sent me I noticed the same hardware configuration of the FDC with the one in my MK83 consists of a WD1797 FDC and a separator external data FDC9229BT.

I then proceeded to:

1) install the EPROM (2716) with the BIOS of my in my MK82 MK83: my MK83 performed correctly BOOT operating system CP / M card MK82.

2) program, a new EPROM in 2716, the contents of the firmware of the MK83 given me at the time by people of Modena, to install it on my MK83 and groped to make the loading of ITS CP / M: this made ​​it possible to develop the my MK83 operating system CP / M for MK83.

Waiting to recover a pair of drives 5.25 "operating with the same features for the system MK3000 and who knows, maybe even its operating system CP / M original, I shall correctly interface a pair of drive 3.5" MK83 firmware and operating system CP / M MK83.

I have my card with MK82 z80 to 2.5MHz and FDC 1771. Upload the bios to F000H and booting the CP / M floppy disk size 8 "SSSD 26 sectors 128byte x track 77 track single side single density.

I took a card with MK83 Z80 B and FDC 1797. Upload your Bios to F800H but I floppy system.

If I try to read a floppy disk with the command MK82 r0,0,1 r0,2,1 and then I see a video that correctly reads sectors.

If I take the bios of the MK82 and MK83 do I put it in the boot with the discs of the MK82. If I try to boot with the bios loaded F800H is unsuccessful because the disk system is configured to "find" entry points to F000H.

I remembered that Fabio Marverti of Modena had a MK83 (call MK83F) that loaded the bios to F800H system disk and had double-sided double-density or rather, the first two tracks contains the double-sided copies / m in size 26 sectors by 128 bytes . The subsequent 75 are composed of 8 sectors of 1024KB of double density on both faces. With this being said I did send the card.

If I program the EPROM with their respective bios and exchange them none of the board gives me the system prompt. However, continue to load their bios to F800H.

On my MK83 I can read a disk sector by sector manually sssd of 26 sectors 128byte.

If I try to read the disk system MK83 fabio Marverti can read sectors of sisetma that are still sssd either side side0 that side 1 side, but if I try to read from track 2 onwards (where the sectors are in 8x1024byte DD) do not read them.

I finally thought that if my MK83 can not read a diskette if you could copy in SD with sysgen cp / m fabio (ie the first two tracks on the disc) on a single-sided disc in SSSD, but this way I miss But the part of the operating system recorded on the hard side 2 side of Fabio.

I did the 'idea of ​​how to create a new disk CP / M.

Finally: I managed to copy sysgen init and disk system Shane, these being generated by a disc of Mk82 SSSD, do not function.


The card is clocked at 4MHz and Chip Series Z80B, a memory chip 4116 × 32 (= 64 Kbytes), a BIOS EPROM 2 content in 2716 from 200ns, and a separator FDC 1797 with external data FDC9229BT. The bios is loaded into RAM at the address F800H and do not have the relevant records of the operating system CP / M. Inserting the EPROM my MK82 instead of his bios (it is loaded into RAM all'idirizzo F000H), the board performs properly Boot disks of MK82 (SSSD 26sect x 77 single-sided single track density).

Fabio Marverti Modena contacted me because they possessed a card very similar, sent me his card that is clocked at 4MHz and Chip Series Z80B, memory chip 8 × 4164 (= 64 Kbytes), a BIOS contained in 1 2732 EPROM from 200ns, and a separator FDC 1797 with external data FDC9229BT. The bios is loaded into RAM at the address F800H and dispose of its disk operating system CP / M (8 DSDD sect traces x 75 double-sided double-density 1,2MByte).

The idea was: if the cards "look alike" I could copy the BIOS Fabio in my to use his records of ssitema and have a complete machine operating system?

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