Newsgroup: it.comp.retrocomputing
Titolo: progetto Hard Disk su un IBM System/23

Ciao a tutti.
Ho il sistema in oggetto, mi piacerebbe entrare in contatto con qualcuno che 
ha esperienza o comunque conoscenze sul sistema ibm specificato in oggetto.
In particolare vorrei sapere se può essere fattibile, collegando una scheda 
scsi su isa tipo la vecchia adaptec1542 (quindi col bios a bordo), far 
riconoscere al System/23 un HD o comunque altre unita disco scsi di piccolo 
taglio.
L'esigenza è ormai fondamentale al fine di fare un backup dei dischi da 8".
Aspetto consigli, grazie.
Nicola

 
Secondo me e' piu' facile trovare dei dischi da 8'' da collegare ad un 
PC, sperando che il formato del System/23 sia leggibile.
txt

 txt 

 sbaglio?
Se cerchi le faq di comp.os.cpm dovresti trovare informazioni su come 
modificare il cavo di collegamento per collegare un drive da 8" al 
controller di un drive da 5.25".
Forse potresti a collegare direttamente uno dei drive del tuo System/23.
Comunque ti includo i dettagli in basso.
Ciao
txt
   The interface on 8" drives and 5 1/4" drives are essentially the
    same.  The 34 lines on a typical 5 1/4" controller are sufficient to
    control most 8" disk drives using soft-sectored disks.  Here, is a
    diagram for a basic conversion cable to allow connection of an 8"
    drive to an IBM-compatible, AT-style (high density) controller.
                                                       8" disk drive
    PC-AT style controller                       Based on Shugart SA-851
    Grnd. Sig.  Sig. Name                             Sig Name  Sig Grnd
      1     2   Double/High Density ->>
                                     >>- Write Current Switch/    2    1
                                    Active Read Compensation
                                    User Customizable I/O pins    4    3
                                     "         "       "    "     6    5
     33    34 **Ready ---------------<<------------ True Ready    8    7
                                     <<-------------#Two Sided   10    9
     33    34 **Disk Change ---------<<----------- Disk Change   12   11
     31    32   Side 1 Select ------->>-----------#Side Select   14   13
      3     4   In Use/Open --------->>---------------- In Use   16   15
     15    16  *Motor On ------------>>------------- Head Load   18   17
      7     8   Index ---------------<<----------------- Index   20   19
     33    34 **Ready ---------------<<----------------- Ready   22   21
                                     <<---------------##Sector   24   23
      9    10   Drive Select 0 ------>>-------- Drive Select 1   26   25
     11    12   Drive Select 1 ------>>-------- Drive Select 2   28   27
     13    14   Drive Select 2 ------>>-------- Drive Select 3   30   29
      5     6   Drive Select 3 ------>>-------- Drive Select 4   32   31
     17    18   Direction Select ---->>------ Direction Select   34   33
     19    20   Step ---------------->>------------------ Step   36   35
     21    22   Write Data ---------->>------------ Write Data   38   37
     23    24   Write Gate ---------->>------------ Write Gate   40   39
     25    26   Track 00 ------------<<-------------- Track 00   42   41
     27    28   Write Protect -------<<--------- Write Protect   44   43
     29    30   Read Data -----------<<------------- Read Data   46   45
                                     <<------##Separation Data   48   47
                                     <<-----##Separation Clock   50   49
    This diagram also works in the other direction--that is, to attach
    high-density 5 1/4" drives to an 8" controller.
    Notes:
    * - It seems to be a logical substitution since the vast majority of
        8" drives have continuously running spindles and instead of
        MOTOR ON require a HEAD LOAD signal.  Also, a controller sends
        MOTOR ON before a DRIVE SELECT.
    **- Most 5 1/4" disk drives do not provide a READY signal but send a
        DISK CHANGE signal on line 34 of the interface.  An 8" drive has
        provisions for both signals.  Likewise, most AT-style
        controllers expect a DISK CHANGE signal on line 34, so lines 33
        and 34 should be connected to lines 11 and 12 of the 8" disk
        connector.  Also, some 8" drives provide a TRUE_READY signal
        which is more useful than the standard READY.
    # - Unused on single sided drives (SA-800/801).
    ##- Used only on hard-sector configured drives (SA-801/851).
    Some 5 1/4" disk drives have the option of providing _either_ DISK
    CHANGE _or_ READY on line 34 (in particular, the TEAC FD55R
    series).  Some 8" disk controllers do not care about the DISK CHANGE
    signal, but must have the READY signal.  If you are attaching a
    high-density 5 1/4" drive to an 8" controller, you may get away with
    making the drive always ready by shorting lines 21 and 22, but this
    may cause a few re-tries when switching sides.  If your drive offers
    a READY signal that your controller can deal with, by all means use
    it.
    The MOTOR ON/HEADLOAD dilemma may also have an alternate solution if
    you are connecting 5 1/4" drives to an 8" controller.  Some 5 1/4"
    drives permit motor turn-on by means other than the MOTOR ON
    signal.  For example, the TEAC FD55R series of drives may be
    configured to turn the motor on based on the state of the IN USE
    light.  The IN USE light can, in turn, be set to turn on only on
    drive select.  Thus selecting the drive automatically turns on the
    motor and neither a MOTOR ON or IN USE signal need be present.
    Another way to handle 8 inch drives on a PC is with a Microsolutions
    Compaticard IV, if you can find one. (MicroSolutions no longer
    offers this product.) It has the necessary software support to
    properly handle 8 inch drives, and in both SSSD and DSDD.  This
    controller can be set up as both a primary controller, or as a
    secondary. It can support 4 drives, of any type, including 2.8 meg.
    It supports two MSDOS 8 inch formats, SSSD (about 250k) and DSDD
    (1.2 meg). It works perfectly with 22disk, and can read and write
    almost any 8 inch CP/M format.

 sbaglio?
Dai anche un'occhiata qui: 
http://www.sydex.com/
txt


sia per l'HD che per i floppy da 8"....il backup is faceva su.... floppy!
N.B.  hai mica per caso anche la stampante?
S.E.&O.
ciao
fm


Attenzione: i floppy da 8" del S/23 sono normalmente scritti in EBCDIC e non 
in ASCII
li puoi leggere con un lettore Ibm da 8" ....per intendersi quelli montati 
su S/34,S/36 e  AS/400.
ciao
fm 


ho anche la stampante, ovviamente è una stampante su collegamento seriale di 
tipo non standard (credo che i livelli di segnali siano di polarità inversa 
rispetto alla rs232c), che però non mi funziona, nel senso che con la 
stampante collegata il sistema non si avvia.
Ciao,
Nicola


probabilmemte un segnale errato proveniente dalla stampante guasta mette 
tutto in blocco...:-(
ciao
fm