Emulator updates

This week the emulator got a couple of major updates:

- I-mode is enabled now. The floating point stuff still isn't
finished and may take a UII (Unimplemented Instruction) or Illegal
Instruction fault. I don't think Prime was using I-mode much at rev
19, but the compilers do support it - just add -32i to the command
line.

- I had a fun time figuring out the disk geometries for Prime's 25
different disk drive models. The emulator supports them all now.
The smallest disk Prime supported was the 32MB CMD (Cartridge Module
Disk), which had a 16MB removable disk and a 16MB fixed disk. Quaint,
eh? The CMD also came in 64MB and 96MB versions, all with 1 16MB
removable disk and the rest as fixed disk inside the drive unit. The
smallest fixed disk was a 60MB drive, model 4711, and the largest was
a 2GB SCSI drive. The reason I added support for different drives is
that I have images of two 600MB SCSI drives, but they had different
geometries and the emulator only supported a single geometry. Now
that the emulator supports all of the drive models and geometries,
it's possible to take an image from any Prime drive and use it
directly on the emulator. To test it, I used MAKE to format,
initialize, and verify all of the different disk models.

- while I was messing with the disk stuff, I added support for 8 drive
units per controller. The emulator supports 8 disk controllers, so
using 2GB drives, it can support up to 128GB of disk per machine.
Makes me wonder what the largest disk configuration was at a real
Prime installation...

Next on the list is I-mode floating point. The floating point code
needs a general re-work, so I'm doing that at the same time. For
example, right now the emulator can't even do simple negation without
losing bits:

list
NONAME.BASIC FRI, JUN 15 2007 10:50:47

10 F = .1
20 I = 1
30 PRINT I:F
40 F = -F
50 I = I + 1
60 GOTO 30
run
NONAME.BASIC FRI, JUN 15 2007 10:51:15

1 .1
2 -.1000000000291
3 .1000000000291
4 -.1000000000291
....
1000 -.1000000000296
1001 .1000000000296
....
5000 -.1000000000313
5001 .1000000000313

I-mode floating point and serialization are the two main roadblocks to
making higher revs of Primos available.

I'm always on the lookout for Prime code, old or new, so if you have
any you want to donate, let me know!

Enjoy!
Jim

.

Relevant Pages

  • Re: command.com wakes up all disk drives on XP (latest patch level
    ... I bet you will see frequent access to the old emulator. ... I have turned on the power management such that hard drives are turned off ... Also any other tips and triks on how to controll disk access. ...
    (microsoft.public.windowsxp.perform_maintain)
  • Re: DSK images to real disks
    ... thought to use the PC and disk images to make real disks for them but I ... downloaded Keil's model III/4 emulator. ... drives was described in the emulator documentation on David's site. ...
    (comp.sys.tandy)
  • Re: CP/M bootable CD?
    ... Zrdos and friends) to get around the 8mb limit of DRI CP/M. ... RAM disk, that comes up already loaded with all the usual CP/M files ... If all you ever used was the A: drive, the CP/M emulator would leave no ... The B: and C: drives might be the PC's floppy and hard drive. ...
    (comp.os.cpm)
  • Re: 3B2 Disks
    ... being able to read the disk in its present format. ... 2 MFM drives on a custom controller. ... SCSI came much later as an add on card. ...
    (comp.sys.3b1)
  • Re: OT-True Image Backup
    ... Make sure the USB drives file system is NTFS and not FAT32.. ... Jaymon is correct in that the disk image you create and save to the D: ... partition of your USB external HDD will have no effect on the other ... Step-by-Step Instructions for Using the Acronis True Image Program to Backup ...
    (microsoft.public.windowsxp.help_and_support)