Philip: Thanks for the error codes. I have no manuals for the Datamaster, so I'm flying blind. The code "09" is inverse-blinking, so there is a real problem. I'll try to pull the chips and re-seat them. The machine worked last summer and wasn't used since then, so I can't imagine the chip going like that. Thanks again for the help. I'll let you know what I find. My company has a UK office (Burdale-Holdings, a trade finance company). If I do need a new chip, maybe we could arrange it so that you could drop it off at our London office (if you're near it) and they could send it to me. ------------------------ Rich Cini/WUGNET - ClubWin Charter Member (6) - MCPS Windows 95/Networking Date: Tue, 15 Jul 97 09:05:06 BST From: Philip.Belben(a)powertech.co.uk To: classiccmp(a)u.washington.edu Subject: Re: Datamaster troubles Message-ID: &lt;9706158689.AA868982856(a)compsci.powertech.co.uk&gt; Rich Cini wrote: screen As promised, I have hunted through my various IBM System/23 (Datamaster) manuals, and found the meanings of the POD (Power-on Diagnostics) error codes. Here is a summary: FF} 00} CPU Failure (!) 01} 02 Failure of first ROS module (Read Only Storage module, i.e. ROM chip) 03 Reserved. If this is highlighted, panic. 04 Failure in bottom 16k of storage, or of storage controller 05 CRT (presumably actually monitor) or DMA failure 06} CRT interface 07} 08 Page registers 09-} ROS failure. There follows a little diagram to tell you which chip 19 } to replace. Yes, the diagram in the manual is made of text, too. ** TOP VIEW OF PLANAR SEEN FROM THE REAR ** _______________________________________________ | ====== ====== <-- NOT FOUND ON | | | 10 | | 11 | <-- SOME EARLY | | =3=40= =3=60= <-- MACHINES | | | | ====== ====== | | | 19 | | 0D | | | =7=60= =1=60= | | *********************** | | =PATCH= ====== * PHYSICAL LOCATION * | | | 18 | | 0C | * OF ROS MODULES * | | =7=40== =1=40= * FOR EACH ERROR CODE * | | *********************** | | ====== ====== | | | 17 | | 0B | -KEY- | | =6=60= =0=60= ====== | | | XX | | | ====== ====== =Y=ZZ= | | | 16 | | 0A | XX=POD ERROR CODE | | =6=40= =0=40= Y=ROS PAGE VALUE | | ZZ=HIGH ORDER BYTE OF | | ====== ====== FIRST ADDRESS IN | | | 15 | | 09 | ROS MODULE. | | =5=60= =0=20= | | ---(CABLE)-------------- | | ====== ====== | ====== | | | | 14 | | 02 | | | 09 | CO-PLANAR | | | =5=40= =0=00= | =0=20= BOARD. | | | | (FOUND ON | | | ====== | ====== SOME EARLY | | | | 13 | | | 10 | MACHINES.) | | | =4=60= | =3=40= | | | | | | | ====== | ====== | | | | 12 | | | 11 | | | | =4=40= | =3=60= | | | ------------------------ | ----------------------------------------------- 1A-} ROS failure on feature card 26 } 27 ROS failure on 2nd printer card 28} ROS failure on feature card 29} 2A-} RAM failure. Table (which I shan't include) of how codes 30 } relate to different sizes of machine. 31 RAM page access failure 32 DMA page register failure 33 Interrupt controller failure 34 Timer interrupt failure 35 Keyboard error. If flashing, keyboard controller. If not flashing, you pressed a key at the wrong moment :-) 36 Printer failure 37 Printer not switched on 38 Diskette attachment failure 39 24 volt rail not reading 24 volts 3A-} belong to add-ons not to the system. I didn't bring the FE } relevant manual pages. General rules for interpretation: Flashing inverse video = fatal error. Non-flashing inverse video = error. Press the Error-reset key and let the machine finish booting. Then run the diagnostics dikette, I suppose. To summarise, it appears you have a dud ROM chip. I imagine the solution is to copy a ROM chip from another Datamaster. If necessary, I can arrange to copy mine, but I don't know off-hand what sort of chips they are. I would also suggest that, unless you too are in England, logistics of getting the chip to you might be hard... Philip. <><><><><><><><><><><><><><> Philip Belben <><><><><><><><><><><><><><> Das Feuer brennt, das Feuer nennt die Luft sein Schwesterelement - und frisst sie doch (samt dem Ozon)! Das ist die Liebe, lieber Sohn. Poem by Christian Morgenstern - Message by Philip.Belben(a)powertech.co.uk