I don't imagine there's much interest in details like these, but I've recently re-done the SCSI bus, swapping in (exceptionally overpriced) Granite Digital cables for the external devices, and replacing the internal 720K 3.5" floppy disk drive with an Insite "floptical" SCSI floppy drive - essentially giving the system the ability to read and write 720K/1.44MB/21MB disks.
Did you have any trouble setting up the SCSI floptical drive? I've had some interest in getting one for my "floppy machine" but haven't found any at a decent price so far. Also, what SCSI format is the interface?
Did you have any trouble setting up the SCSI floptical drive?
The Trantor SCSI adapter I'm using lacks BIOS support for Floptical drives, so I'm relying on Adaptec's ASPIDISK.SYS driver. No troubles though - the drive itself behaves nicely, and the regular DOS format commands cooperate with it as well.
The peak wattage of the Floptical drive (nearing that of a hard-drive) concerns me a bit, given the weak, 67-watt Tandy supply, and everything else installed. I almost wonder if a SCSI LS-120 drive might be a better way to go...
Also, what SCSI format is the interface?
This particular drive is 50-pin IDC, SCSI-1.
sliderider wrote:
But can it read/write 2.88mb floppies?
No, but it will supposedly read 800K and 1.4MB Apple-formatted disks. 😀
sgt76 wrote:
Amazing condition... did it come like that, or did you have to restore it?
The system itself arrived in pretty nice shape, and (as with most Tandy systems I've received) just needed a really good scrubbing. I did have to rivet a new set of rubber feet onto the computer case, but that's about the extent of things.
Guess it's been awhile since I last updated the specs for this system (not that anyone should care)...
The Trantor card was replaced by a Rancho RT1000B earlier this year. Given its BIOS-level support for Floptical drives, support for a 2GB bootable partition, and throughput increases besides, this particular SCSI adapter is, in my opinion, the best available for use in Tandy 1000 systems.
The 5.25" floppy drive was removed, due to concerns about its proximity to the CPU accelerator.
The Tandy CM-5 monitor was replaced with the higher-quality CM-11 model.
Lastly, and despite the decent General MIDI playback capabilities of the installed AudioTrix Pro, the MT-32 was recently (today) supplanted by a CM-64 and CM-300 combination pair. Because of the MIDI and audio chaining in that pairing, and lack of additional hardware to deal with it in a more elegant manner, I'm using SysEx strings and batch files to disable MIDI channel reception between devices, as needed.
The SCSI bus needs to be redone at some point, and the raucous power-supply fan begs to be replaced with something quieter, but with that, this system will have met its final configuration.
Pretty cool. This system uses many of the tricks I used in my super XT.
I have four of these Teac FDD to SCSI adapters that supposedly allow any density floppy drive to work on the SCSI bus, but I ended up not bothering due to the high memory requirements to get everything going. I ended up just using a multi-I/O controller (without BIOS support) and a real 1.44 meg floppy drive with a utility called "2M" for 1.44meg floppy support. The TSR uses just a few KB and can be loaded/unloaded when needed.
I presume that your IO-DATA adapter uses an IBM SLC2-50 or 66 CPU. You are currently running at 32 MHz. I would guess you are using the external 4X multiplier provided by the adapter. It should be possible to enable the CPU internal multiplier as well (can be selected for 1X, 2X or 3X) which would allow you to run at 48 or 64MHz. You may have to change a surface mount resistor on the IO-DATA adapter to toggle between 3X and 4X to get the right speed combination. I have a "Buffalo" adapter that uses a TI486SXL which I run at 48MHz (3X external multi, 2X internal multi). I also have two adapters based on the IBM 486s, and you can use a utility by Kingston or Evergreen to select the internal multipliers on those CPUs.
Pretty cool. This system uses many of the tricks I used in my super XT.
We should probably compare notes or something. In particular, I'd be curious to know what kind of 3DBench score you're getting. I managed to eke out 7.4 FPS, which isn't fantastic or anything, but does allow for smooth playback of the CD-ROM version of Dune...
One of the things I'm particularly proud of with this system (and that a significant portion of time was spent on) is the DOS configuration. I posted the full config on the Vintage Computer forum a few months back, but you're likely someone who might appreciate it, in case you didn't see it there:
I presume that your IO-DATA adapter uses an IBM SLC2-50 or 66 CPU...It should be possible to enable the CPU internal multiplier as well (can be selected for 1X, 2X or 3X) which would allow you to run at 48 or 64MHz.
It's the 50 MHz version. From the CONFIG.SYS, you'll probably notice that I'm using the Evergreen driver to enable the caching. Unfortunately, (and I'm not sure if this is a Tandy quirk, or some other limitation) the software multiplier does absolutely nothing. I've tried it at /1, /2, and /3, and with and without the /BL switch, to no effect. Unless you know of another utility, I'm likely stuck with just the 4x hardware multiplier. That said, 32 MHz isn't particularly shabby, and Norton SI reports the system as being comparable to a 386DX-33 - close enough for rock 'n' roll.
The IO-Data adapter I was using had the DLC version of the IBM 486 CPU, but it should be identical to the SLC in every way except for the external bus.
I remember trying software from at least two or three different vendors, but could only get the multiplier to change with one of the packages. Unfortunately, the system in question no longer really exists (sold the motherboard), and I don't currently have a 386 board that is compatible with my adapter. But, I seem to recall that I was using the Kingston version of the utility. I most likely made notes somewhere. I will try to figure it out. I highly suspect your CPU would have no issue overclocking.
BTW, I highly doubt your benchmark software would run on my XT. It's using a V30 CPU. (My CPU adapters are for my 286 and 386 motherboards).
