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The FrankenTandy 1000 SL: fastest XT in the world?

Fanatik said:
Could this same mod be performed on a 1000hx? I have wondered about switching out the oscillator to run a V20hl at 16mhz.
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I have no idea. This is possible on the SL because most things requiring a clock have their own independent clock. The SL actually uses dual clock oscillators. There are 16Mhz, 24MHz, 28.6MHz and 32.something which are required for several different IC's.

On the HX i have no idea,i never looked into the technical documentation. But if everything is tied to a single clock it might be impossible.

On the SL the 24MHz signal seems to be used only for CPUCLK, which means if i change this signal only i'm just going to change the CPUCLK. If a system is tied to a single clock, changing just by a small margin will likely turn it into an unstable mess.
 
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Trixter said:
FYI, I published a new release of TOPBENCH with your result in the database. It's faster than most of the 12Mhz 286s, which is a little scary. Can pick it up here: https://github.com/MobyGamer/TOPBENCH/releases/tag/0.38.h
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Thank you!

Why scary? :confused:

Keep in mind i'm still going to update these results later. That score still doesn't reflect the faster memory timings, even if this just results in a small improvement.

We have to put this all into perspective. A 12MHz 286 CPU is always going to be faster than my V30HL at 16.6MHz. All those 12MHz 286 systems that the FrankenTandy beats might be hampered by dog slow memory timings. OEM machines always seemed slower than generic AT clones with the same specs.

My FrankenTandy at 16.6MHz seems to be more inline and showing almost as fast as a 0WS 10MHz 286 AT clone. My 286 system for instance (its not at TOPBENCH yet) is a quite fast 286 system can clock at 16Mhz and 8Mhz. At 8MHz my 286 is slower than my FrankenTandy. The difference is a mere 250 Dhrystones in Checkit. So my estimate is that my FrankenTandy is almost as fast as a 10MHz 0WS 286 system. This seems to go inline with the difference between the FrankenTandy and the IBM 5162.
 
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keenerb said:
Don't leave the RLX out. It's the best pizza box ever, has all the advantages of the TL/3 except only one ISA port, but it has a "real" parallel port/PS2 mouse/etc.
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Side note, has anyone ever tried an ISA backplane extender in here to get more than one slot? :)
 
Here's just a slight improvement done by BIOS finetuning:

[UID7D94DB0]
MemoryTest=594
OpcodeTest=309
VidramTest=410
MemEATest=379
3DGameTest=299
Score=26
CPU=NEC V30HL
CPUspeed=16.6 MHz
BIOSinfo=Tandy BIOS 1.04
BIOSdate=19880622
BIOSCRC16=7D94
VideoSystem=CGA
VideoAdapter=Tandy 1000 SL/TL
Machine=Tandy 1000 SL (FrankenTandy)
Description=Tandy 1000 SL modded with a 50Mhz OSCI, 0WS
Submitter=CarlosTex [@Vogons] [@VCFed] forums


Well the system will not boot at 18MHz, i think it is already running almost at its limit. I'm still waiting for some faster memory to arrive, which probably won't make a difference anyway. I just want to make sure i did everything i could.

To do better than this i would have to overvolt slightly the CPU, which would involve bending pin 40 and pin 20 and feed it with an external power source. I guess the CPU would tolerate a little more than 5.5V and it could have higher frequency potential. But i'm not too sure this is worth to do, although it would make the FrankenTandy even more "Frankenstein".

I'm pretty happy with its performance.
 
CarlosTex said:
Here's just a slight improvement done by BIOS finetuning:

[UID7D94DB0]
MemoryTest=594
OpcodeTest=309
VidramTest=410
MemEATest=379
3DGameTest=299
Score=26
CPU=NEC V30HL
CPUspeed=16.6 MHz
BIOSinfo=Tandy BIOS 1.04
BIOSdate=19880622
BIOSCRC16=7D94
VideoSystem=CGA
VideoAdapter=Tandy 1000 SL/TL
Machine=Tandy 1000 SL (FrankenTandy)
Description=Tandy 1000 SL modded with a 50Mhz OSCI, 0WS
Submitter=CarlosTex [@Vogons] [@VCFed] forums


Well the system will not boot at 18MHz, i think it is already running almost at its limit. I'm still waiting for some faster memory to arrive, which probably won't make a difference anyway. I just want to make sure i did everything i could.

To do better than this i would have to overvolt slightly the CPU, which would involve bending pin 40 and pin 20 and feed it with an external power source. I guess the CPU would tolerate a little more than 5.5V and it could have higher frequency potential. But i'm not too sure this is worth to do, although it would make the FrankenTandy even more "Frankenstein".

I'm pretty happy with its performance.
Click to expand...

Its the first time i hear about someone overvolting something as ancient as the v30 and is so cool :D
 
I just saw LGR's video on his Tandy 1000:

One of the games he demonstrates is LHX Attack Chopper, and it runs horribly slow. Can you make a quick video of this super-fast Tandy running the game? I bet it can run it pretty smoothly!
 
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I "designed" a dual Oscillator switch for this Tandy in order to be able to not only use the super clocked 16Mhz but also lower clocks to make this system perform a little more like a Tandy 1000 SX. This is difficult because of the 8088 vs NEC V30 difference but i've found that a crystal value between 16 to 18 MHz give a similar performance to a Tandy 1000 SX. Right now i'm using a 16.275Mhz oscillator i cannibalized from an EGA card, so i get 5,42 MHz in fast mode and 2,71 Mhz in slow mode. At slow mode the performance is close to the IBM 5150.

Unfortunately there seems to be no way of toggling the speed except by the mode/speed utility via DOS or by setting the EEPROM with the SETUPSL utility. It is also unfortunate that after a soft boot the system reads the EEPROM again and sets whatever is defined in the EEPROM. I wish there was a key that could be pressed during boot that could set the speed. I've seen that F4 key does that for the Tandy 1000 SX and TX, but that does not work in the SL. I also had a read through the SL users manual and no mention of a key to toggle the speed during boot.

I know that speed can be controlled by toggling bit 3 on port 62, 1 for full speed and 0 for normal speed, so i'm wondering since i have plenty of space in the XT-IDE EEPROM, to write a BIOS extension that looks for a certain keypress to toggle the speed. This would make it very useful to run bootable games at proper speed.


Check this link for a photo of the dual oscillater switch i breadborded :

https://pbs.twimg.com/media/DuipxfeW0AAzihw.jpg
 
necro this thread...
the "FASTEST XT" is the Olivetti PCS86 from 1989 (not 1986 like ppl think)

The PCS86 has a nec v30 8mhz or 10mhz nec v30, 640kb base ram, EMS 4.0 onboard ram ability, bypassing the slow 8-bit isa bus for the extra ems memory, a upto 1.44mb floppy 2 drive controller, a IDE "XTA" 2 drive controller (best to build XTA to 8bit CF adapter https://www.facebook.com/OlivettiProdestPC1/posts/1606276686257414 for hints), 3 full-length 8-bit ISA slots on a riser card, Integrated Paradise VGA chipset (its 256kb), a RTC with 3.5v battery, PS/2 keyboard & mouse ports, vga port, parallel & serial ports. Plus 2x 30 pin simms for upto 32mb additional ram (2x 256kb or 2x 1mb or 2x 4mb or 2x 16mb).
nec v30 8mhz may be upgraded to a 16mhz nec v30HL
Its possible to run any version of windows 3.1x if kernel from windows 3.1 build 3.10.034e "janus" in real mode & still access 32mb of EMS ram (although a v30s/8086s should be limited to 16mb ram address, other 16mb will be unusable/invisible to a 8086 class cpu)

TLDR: this PCS86 has all/most ports u need, can be a 16mhz NEC V30HL (100% 8086 compatible + 30% faster per mhz/clock than a 8086) with 16mb usable ram via FAST ONBOARD EMS, access upto 2x 1.44mb floppy drives (or usb floppy emulators), use a CF card as a 8-bit XTA hard disk on onboard IDE (limited to 8-bit even over isa anyways, i suggest ontrack DDO to format card), can run ms-dos 7.10 & windows for workgroups 3.11 in real mode and still see 16mb ram (if kernel from windows 3.1 build 3.10.034e "janus" is used) with ms-dos 7.10 (fat32/lfn support). It could use an isa ethernet card and access the internet via ie 5.01 or opera 3.62, even use calmira II 3.31/camira xp 4.0b for a 95 or xp like shell with lfn support. ISA usb 1.1 cards exist as do drivers for dos/win3.x. that would leave 1 isa slot free for a sound card (unless you like "beeps" only, i suggest soundblaster 2.0), barely fully equipping system to "usable", but usb card might best be swapped for a 1mb (maybe 2 if 8-bit supports it) 8-bit isa video card to max out performance & just ftp files to the pcs86 system
I HIGHLY suggest using the "best possible" 1mb 8-bit isa video card to max out performance & just ftp files to the pcs86 system and not bother with the usb 1.1 card (its no better than using the gotek usb floppy drive emulator anyway)


its as 96% fast a 12mhz 286 with 16mb ram (as both have it on a 16bit bus on the motherboards) & can run windows for workgroups 3.11, if the suggested "mod" is done to the kernel file used. Its useful for mp3 listening, text editing, basic internet/email access, the older dos games like lemmings/prince of persia/wolfenstine3d fixed to 8086 mode (other OLD 286, some 386 era, games fixed in same way, doom???) maybe some ascii rouge likes?

this in my testing is the fastest XT to exist, it can use the 16mhz nec v30HL and has 16bit access to 16mb of ems 4.0 ram, it even has 3 full length isa 8-bit slots so better (read best possible over 8-bit isa) video, ethernet and sound are possible at same time...using onboard XTA (with a real XTA hdd or a custom made XTA to CF card in 8-bit mode adapter) is just a fast if not slightly faster, as an 8-bit XTIDE card (ATA). Very rare, very powerful...just able to run wolfenstine 3d, fixed for 8086, at 320x200 full (not shrunk) and feel very playable.
 
aazard: If you could run TOPBENCH and report back the results (look in DATABASE.INI after you add your system) for your 16 MHz NEC V30HL, I'd be very appreciative. We don't have that system in the database yet.
 
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