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    CPM BIOS, BDOS, CCP layout on Disk vs RAM

    It’s been a while but IIRC BNK1 is loaded with banked portion of CCP, BDOS & BIOS. Plus the disk images are sysgen’d backwards (last sector first) onto disk so the bootloader loads to high memory down to the bottom of the BDOS (or CCP).
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    Ohio Scientific Challenger 4P C4PMF garbage screen

    Update: Got the Gotek working. Turns out it was strapped for DS1… which is usually the case when used with "twisted" (PC) drive cables. The C4PMF uses non-"twisted" (strait thru) cables so I had to change the drive jumpers for DS0. Now everything works as expected… Well, almost… the OSIHFE tool...
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    Ohio Scientific Challenger 4P C4PMF garbage screen

    SUCCESS! Finally got the real 5.25" floppy booting… turns out that on the KLyball D-13 the /DRIVE READY 1 & /DRIVE READY 2 lines have to be grounded for 5.25" drives… The photo from the What jumpers worked for me thread showed 11 & 12 shorted… I'm guessing for 8" drives. For 5.25" drives 12 &...
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    Ohio Scientific Challenger 4P C4PMF garbage screen

    Are you using these with a Gotek? If so can you provide the .CFG files you use?
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    Ohio Scientific Challenger 4P C4PMF garbage screen

    Ok, got the data separator (YAY!); built & installed it… and after some troubleshooting works find with a 5.25" floppy drive (strapped for 300 RPM). Disconnect (real) floppy; connect Gotek… and… can't find track zero? Humm… I tried several of the C4P images from osiweb.org… but none of them are...
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    TRS-80 Model 4 CRT

    FYI: TRS-80 CRT’s are available on eBay: <TRS-80 CRT>
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    OSI reproduction boards: Who is interested?

    Looking for any info on “Grant's data separator board”.
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    Ohio Scientific Challenger 4P C4PMF garbage screen

    Can you provide more info on the data separator? I’d like to use a Gotek with my C4PMF.
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    OSI reproduction boards: Who is interested?

    Ran across this thread looking for information about floppy data separators. I got a C4PMF off eBay; swapped out the memory for a glitchworks 48K; replaced two backplane connectors and… it works! Almost… :( After some hair pulling I determined that the 5.25” floppy (MPI B-51/52) wasn’t returning...
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    Bit7 in CP/M characters.

    Oops: I meant ASCII not ANSI. ;-) CP/M doesn’t do ANSI.
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    Bit7 in CP/M characters.

    There’s nothing in CP/M having anything to do with terminal specific character sequences (other than ANSI). Most Infocom games just used ANSI and didn’t do any terminal specific sequences. For the rare ones that did an installer was included to configure the game for whatever terminal the user...
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    z80 vs 8080... Which to develop in and why? (from a historical POV)

    Being 8080 compatible was only important for commercial software where selling to the widest audience was necessary. All the customer specific code I worked on was always Z80. An experienced Z80 developer could write code that out performed 8080 code easily.
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    RAMdisk CP/M 2.2 (MDFRMT)

    Not sure why you’re reinventing the directory structure… Why not just add the MDisk R/W code to the BIOS and let CP/M deal with the directories?
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    TRS-80 diagnostic/ICE card

    Just an FYI: There’s a Z80 version of the ROMulator available for $40!
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    Really cheap CP/M

    Is an image for the SD card available anywhere to download? BTW: I’ve got a github project to map logical drives B: thru P: to any physical partition 1-65535. It implements •NIX type directory commands (MKDIR, CD, PWD) to navigate thru the partitions like directories. See HFS4CPM
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    Hardware Breakpoint for debug

    FYI: there’s a Z80 and a 6502 version of the ROMulator… it’s not a full ICE but can do a lot for a minimal cost. Z80 ROMulator
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    Low cost Z80 ICE

    No but I’ve been quite happy with the Z80 ROMulator.
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    Thought experiment: CP/M directories

    See my notes on this at HFS4CPM
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    Thought experiment: CP/M directories

    A few years ago I replaced all my (failing) floppy disk systems with s100computers.com’s dual CF/IDE cards. FYI: An 8 GB CF card can hold 1024 8 MB ”hard” CP/M partitions. Using this I came up with a hierarchical directory system. All I needed was a way for a “CD” application to change the...
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    Please cry with me - My Osborne 1 chewed up my DD boot disk :( Advice sought.

    I’ve had bad experiences with old (cheap) floppy media (sounds like an ED problem… TMI? ;-) By all means clean the heads but you can expect old floppies to disintegrate occasionally. All the more reason the GoTek is a god sent.