System MK3000

In another part of the site where I discussed the research done on the history of the Italian card Ferguson Bigboard I, I reported some system information MK3000 produced in Italy in 1983 by the ADE Electronics Palazzolo Milanese (Milan). In December 2012 I managed to get hold of this system. E 'consists of a board with MK83 Z80A processor, two Z80A PIO (for dual port printer, mapping i / o keyboard port, one Z80A SIO / 0 for two-channel RS232, one Z80A CTC for system timer and an FDC 1797 for 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 (720 KB DS / DD)
Unfortunately, the hardware was not completed with the respective software CP / M, although the visual conditions of the hardware are really excellent.

DSCN0020

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 of use to CNUCE Pisa. If it was necessary to pierce the cards and then read them to a machine to launch their own programs, was now sufficient take them diskettes 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 that SSSD 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 extracted from the manual which I managed to get hold of the site CNR - ISTI of Pisa:

MK3000

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

Unfortunately, the system was not complete the boot disk of the operating system CP / M and its utility, so after you connect to the card using a PS2 keyboard interface PS2-Parallel, you connect a TV monitor with a composite PAL analog, power supplied with an ATX power supply I proceeded to turn the board failed to achieve the initial clear screen, the message "System Monitor 4.2" and the prompt "m>". There were also many other operational commands firmware as the memory dump, etc. I then did some 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 there would be to modify the normal 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 a drive adapter I had homebuilt in January 2012 and it is working perfectly with my MK82 whose scheme is as follows:

DriveBus

In it the 50-pin IDC connector is directly connected to the 50-pin IDC connector present 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 8 ". The main motivation to achieve 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 sngoli the signals are attested on different connector pin IDC 50-pin (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 content of the EPROM (2,716) 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 placed at the address 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 bout a year ago, I got to be contacted by a person of Modena which had an identical card MK83 used to run her knitting machine. Looking at the photos you sent me I noticed the same hardware configuration of the part FDC with that present in my MK83 consists of a FDC WD1797 by a separator and 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 2716, the contents of the firmware of the MK83 given me at the time by the person of Modena, to install it on my MK83 and groped to make the loading of ITS CP / M: this allowed to develop on my MK83 operating system CP / M for MK83.

Waiting to retrieve a pair of drive 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 3.5" drives with MK83 firmware and operating system CP / M MK83.

I have my card with MK82 z80 at 2.5MHz and FDC 1771. Upload the bios to F000H and booting the CP / M from floppy disk size 8 "x SSSD 26 sectors 128byte 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 you 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 I put in I boot disks with the MK82. If I try to boot with the bios loaded F800H not be successful because the system disk is configured to "find" entry points to F000H.

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

If I program the respective EPROM with their bios and exchange them none of the board gives me the system prompt. However, continue to upload 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 which side one side, but if I try to read from track 2 onwards (in which sectors are in 8x1024byte DD) do not read them.

I finally thought that if my MK83 can read a diskette is in SD if I could copy with sysgen the 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 fabio.

I have no more 'idea how to create a new disk CP / M.

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

Summary:

The card is clocked at 4MHz and Chip Series Z80B, a memory chip 32 × 4116 (= 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 of my MK82 instead of his bios (this is loaded into RAM all'idirizzo F000H), the card performs properly Boot from the disks of the MK82 (SSSD 26sect x 77 track single sided density).

Fabio Marverti Modena contacted me because they possessed a card very similar, sent me his card that has a 4MHz clock and Chip Series Z80B, a 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 are completely fitted its disk drives operating system CP / M (DSDD sect 8 x 75 track double sided double density 1,2MByte).

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

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