MiSTer FPGA Forum

pgimeno wrote: ↑Thu Jun 23, 2022 9:16 pm

jca wrote: ↑Thu Jun 23, 2022 8:14 pm It still does not work, running the command manually in the console gives:
ERROR: '/media/usb0/games/PCXT/hdd.img', file size does not match standard CHS geometry (x:16:63), please specify geometry explicitly with -g

I think someone mentioned having this error but it still worked for him. Should I try with a smaller disk, like 20MB?

That error means that the size of the file you created is not a multiple of 516096 bytes.

The standard geometry it's talking about is x cylinders (x varies), 16 heads, 63 sectors per head. A sector is 512 bytes. Since the only parameter you can vary is the number of cylinders, the size must be an exact multiple of one cylinder, that is, of 16*63*512 = 516096 bytes; otherwise you have to specify a different geometry (cylinders, heads and sectors) with the -g parameter by editing the serdrive command in the script that mounts the disk.

jca wrote: ↑Thu Jun 23, 2022 9:39 pm This thing is driving me crazy:
On Github for serdrive I found default is a 32 MB disk, with CHS geometry 65:16:63.
I tried it but it did not work. After calculation it happens this is not 32MB but 33.54624MD.
My disk is 33,554,432 bytes, how do I calculate the damn thing?

pgimeno wrote: ↑Thu Jun 23, 2022 9:49 pm

NML32 wrote: ↑Thu Jun 23, 2022 9:29 pm What's the easiest way to create a raw disk image that has the correct geometry? I'm having the same issue with every raw file I create.

With Linux, try with:

Code: Select all

dd if=/dev/zero of=<target_name> bs=516096 count=<number_of_cylinders>

For a specific size, divide the required size in bytes by 516096 and round up to obtain the number of cylinders.

For example, for 20 MiB, that's 41 cylinders because 20*1024*1024/516096 = 40.63492...

dd if=/dev/zero bs=$((16*63*512)) count=<number_of_cylinders> of=<target_name>

remax wrote: ↑Thu Jun 23, 2022 8:32 pm

Akuma wrote: ↑Thu Jun 23, 2022 6:34 pm Did you try "digger" by any chance?

Digger works as far as i can see

wark91 wrote: ↑Fri Jun 24, 2022 7:46 am After some tests, I found one game Commander Keen 4 (CGA version) raised a divider issue at the start of the game.

66dcf6070a4bc5c8933815b15dab7145ddcccb959f8f43af2a0449b085a04366  AUDIO.CK4
5734c4eee44eab5b0a296297b27ae6f541ce33382bda5dcfd8b674bb33f23a96  CGAGRAPH.CK4
01186f8cb99257b69a4f475186deb9ba79b872ed52378131c79c21f6344753ea  GAMEMAPS.CK4
cfd35e100d4da507d773860642e8fcd02638aeea03d78ba4aa0a51589ba99116  KEEN4C.EXE

66dcf6070a4bc5c8933815b15dab7145ddcccb959f8f43af2a0449b085a04366  AUDIO.CK4
5734c4eee44eab5b0a296297b27ae6f541ce33382bda5dcfd8b674bb33f23a96  CGAGRAPH.CK4
01186f8cb99257b69a4f475186deb9ba79b872ed52378131c79c21f6344753ea  GAMEMAPS.CK4
f838ee104b4670a1454956b9de5bd38118551fb5eaa55a8aa11ff6c6e5850eb0  KEEN4C.EXE

NML32 wrote: ↑Fri Jun 24, 2022 1:30 pm What version of DOS is recommended? Currently I'm using MS DOS 3.3 but I'm thinking maybe MS DOS 5.0 would be better.
Any suggestions for this PCXT core?

breiztiger wrote: ↑Thu Jun 23, 2022 7:12 pm

As for the HD controller, I would settle for having a proper implementation of an 8-bit IDE interface on the 300h I/O port, so that I can use it with the XTIDE Universal BIOS in its default configuration.

Pc xt has st506 not ide for thé real world

• Also known as IBM XT, PC/XT, XT
• Type Personal computer
• Release date March 8, 1983; 39 years ago
• Discontinued April 1987
• Operating system IBM BASIC / PC DOS 2.0-3.20 / PC/IX / SCO Xenix / Minix
• CPU Intel 8088 @ 4.77 MHz
• Memory 128–640 KB RAM
• Storage 10–20 MB hard drive
• Graphics MDA, CGA

• Version 3.3 (OEM) – First version to support 3.5-inch, 1.44 MB floppy drives and diskettes, extended and logical partitions, directory tree copying with XCOPY, improved support for internationalization (COUNTRY.SYS),[58] networked file flush operations[59]
• Version 3.3a (OEM)
• Version 3.30; Release date: February, 1988[60]
• Version 3.30A (OEM, DTK); Release date: July, 1987[61]
• Version 3.30T (OEM, Tandy); Release date: July, 1990[62]
• Version 3.31 (Compaq OEM only)[nb 1] – supports FAT16B with partitions larger than 32 MiB;[nb 2] Release date: November, 1989[63]

dmckean wrote: ↑Fri Jun 24, 2022 1:41 pm

NML32 wrote: ↑Fri Jun 24, 2022 1:30 pm What version of DOS is recommended? Currently I'm using MS DOS 3.3 but I'm thinking maybe MS DOS 5.0 would be better.
Any suggestions for this PCXT core?

MS DOS 3.3 is small, lightweight and fast on an XT. The later versions use up more conventional memory.

Malor wrote: ↑Fri Jun 24, 2022 1:42 pm

breiztiger wrote: ↑Thu Jun 23, 2022 7:12 pm

As for the HD controller, I would settle for having a proper implementation of an 8-bit IDE interface on the 300h I/O port, so that I can use it with the XTIDE Universal BIOS in its default configuration.

Pc xt has st506 not ide for thé real world

While true, ST506 was horrible, and you could only tell the difference if you were running really low-level stuff, like calling into the BIOS on the controller to lay down a low-level format.

Simulating all that nonsense would be a huge pain for almost no benefit. IDE is tremendously better and will run about 99.9% of software in exactly the same way. It's not "authentic", but doing crap like low-level formats when your backing store is a disk file on a modern filesystem is just silly.

I mean, with ST506, you had to read the bad sectors off a sticker on the top of the drive (all drives had bad sectors), and enter those into the low level format BIOS routine in your hard drive controller. What possible purpose would replicating that behavior serve?

spark2k06 wrote: ↑Fri Jun 24, 2022 2:03 pm To a real PCXT you can also add an ISA card with a real IDE controller, the ST506 is just another ISA card with another type of HD. So let's look at it like this, it's as if we had replaced one card for another in a PCXT.

spark2k06 wrote: ↑Fri Jun 24, 2022 2:03 pm

Malor wrote: ↑Fri Jun 24, 2022 1:42 pm

breiztiger wrote: ↑Thu Jun 23, 2022 7:12 pm

Pc xt has st506 not ide for thé real world

While true, ST506 was horrible, and you could only tell the difference if you were running really low-level stuff, like calling into the BIOS on the controller to lay down a low-level format.

Simulating all that nonsense would be a huge pain for almost no benefit. IDE is tremendously better and will run about 99.9% of software in exactly the same way. It's not "authentic", but doing crap like low-level formats when your backing store is a disk file on a modern filesystem is just silly.

I mean, with ST506, you had to read the bad sectors off a sticker on the top of the drive (all drives had bad sectors), and enter those into the low level format BIOS routine in your hard drive controller. What possible purpose would replicating that behavior serve?

To a real PCXT you can also add an ISA card with a real IDE controller, the ST506 is just another ISA card with another type of HD. So let's look at it like this, it's as if we had replaced one card for another in a PCXT.

breiztiger wrote: ↑Fri Jun 24, 2022 4:03 pm as i remember i haven't get any ide controler on xt pc

i know that today we have this kind of isa card but in 1980s, i don't think so

and to have a real xt core we must have original setup

breiztiger wrote: ↑Fri Jun 24, 2022 4:03 pm as i remember i haven't get any ide controler on xt pc

i know that today we have this kind of isa card but in 1980s, i don't think so

and to have a real xt core we must have original setup

Bas wrote: ↑Fri Jun 24, 2022 5:16 pm There's always SCSI if you want a challenge! On a more serious note, having a SCSI interface figured out could benefit Amiga, AO486 and more computer cores.

breiztiger wrote: ↑Fri Jun 24, 2022 4:03 pm as i remember i haven't get any ide controler on xt pc

i know that today we have this kind of isa card but in 1980s, i don't think so

and to have a real xt core we must have original setup

thorr wrote: ↑Fri Jun 24, 2022 6:04 pm I am in support of SCSI support. It certainly existed back in the day and was often considered the superior option. If this can be taken from the Sparcstation core, that would be great. However, I have my doubts that it would just drop in unless it is equivalent to an Adaptec controller because SCSI required Adaptec drivers from what I recall. I can't remember how you can boot off it before loading the drivers (chicken and the egg). Maybe a floppy would be the boot drive. It seems that IDE support is the simplest overall solution though. I don't know if IDE requires a certain version of DOS, but being able to run DOS 3.1 should be possible to be more authentic with the core IMO. Also, I am fully in support of a proper full low level IDE implementation rather than a hack so it will work with any OS. Of course, I will happily accept whatever we can get.

edit: also, building a convincing SCSI chip on an FPGA would probably be a freaking science project. That could take a year or more, all by itself.

Malor wrote: ↑Fri Jun 24, 2022 6:36 pm
Doing ST506 will be really hard and really unnecessary. There's ZERO benefit to running MFM or RLL. All it adds is irrelevant hassle. It's backed by a file, it's not real hardware, so adding all that complexity does. no. good.

Look at what the Monotech NuXT is doing... it's a new motherboard that takes an 8088 or NEC V10 chip. The design principle seems to be "the best possible XT". It provides 832K of total RAM, onboard VGA, and onboard 8-bit IDE. They're not interested in trying to simulate ST506. Not having to deal with low level formatting is a feature, not a bug.