Possible PUTR bug?

Fred Cisin cisin at xenosoft.com
Sat May 11 19:53:55 CDT 2019

I wish that I were to have met you 40 years ago!
Learning that stuff by error, error, error, trial, and error was 

Grumpy Ol' Fred     		cisin at xenosoft.com

On Sat, 11 May 2019, allison via cctech wrote:
> My Solution is easier, least for me.
> I have a few Z80 CP/M machines with 765A in it and if it can't read it
> its likely due to being hard sectored or M2FM.  I has 3.6, 5.25 and 8"
> and  the 5.25 are Teac FD55gfh which are dual speed and can do all
> modes. With my own software and utilities it does whatever even RX180,
> RX50, RX33, and RX22/23 formats from the DEC pool.
> The PC machine for when that stuff is needed is a DELL pizza box that
> has 32mb of ram and 486dx/66 (ISA/ISA16) and can run dos though NT4 as
> needed as I have a buttload of ST3660As as media for them (have two as a
> spare).  That machine uses a combo IO controller for the FDC seems to do
> what I ask of it.  Also an old Compag with similar features and PII and
> 32MB and also does Ethernet but the disk controller is a newer ISA16
> using a combo chip and most of the combo chips after late 90s-ish seem
> to have an even shorter VFO sync window (flash blindess).
> I neither expect nor desire modern machine with anything past NT4 to
> behave well with old disks.  Though Mini-ITX boards all seem to support
> everything and anything and have all the legacy ports.  They all run
> linux and if needed a partition (60mb of disk is trivial) for MSdos
> 6.22 or freedos.
> Oh, unless its under threat the OS is linux, freedos, or if required XP
> Though the latter is usually under VMware or Virtualbox on Linux..  I
> just got tired of all the winders hassles and requirements for insane
> hardware needs every few years.  Most stuff runs fine under dosemu or wine.
> As to RT11, I have run mostly V5.0x and as needed if a device required
> it a later driver borrowed from V5.04 or later.  It just seems to work
> with out much pain.
> As to running a RX50 on a PC...  That drive was a neat thing but its
> mostly the interface is incompatible with most standard floppies and
> a FD55A/B or any of the 48tpi 40 track drives will read and write the
> media.  I make a point of only using it on PDP-11 as transfer media,
> its low density so its marginal for much.  Keep in mine that drive
> select is used to select the A or B drive of a RX50 there is no side.
> They had a terrible track record for reliability.  I can put Two RX33
> [teac fd55gfh] in the same space and store more.  Some to think of it
> most Late PC 5.25 and 3.5 inch drives are incompatable with old standard
> [TM100 and that era] as many do not have a 1 of 4 drive select jumper
> and use the funky PC only twist cable.
> I neatly sidestep all of the cruft and hacks needed for super wizbang
> winXP and later machines.  I figure if I'm going to play with old
> hardware I need to retain the old hardware to maintain them.  So I
> retained the best of the best old PCs as they bulk of them are crap.
> I buy new hardware that is not neutered.  Mini/Micro-ITX board with
> atom or celeron CPUs (really all that's needed) are cheap and easily
> built up into linux boxes or if you must any of the older 32 bit
> winders incantations.
> Allison

More information about the cctalk mailing list