GloriousCow wrote on 2023-09-11, 22:49:

The Book8088, even with an 8088 CPU, isn't quite 100% cycle-accurate to an IBM PC. Can we fix that? Well, yes we can!

https://martypc.blogspot.com/2023/09/hacking- … r-accuracy.html

That's pretty awesome research!

--
Now, mouse driver for CH375 chip, anyone?

the3dfxdude wrote on 2023-09-12, 03:01:

This thing is attracting tinkerers primarily so who knows.

Someone made a voltage mod for this to make some sweet V20 liquid nitrogen overclocking!😅

n0p wrote on 2023-09-12, 08:40:

Now, mouse driver for CH375 chip, anyone?

Technically, it's possible for sure. There are vintage DOS mice drivers for real USB controllers, even.
They worked with text-based applications like Norton Commander and its clones (Volker's Commander etc).
There also were USB drivers on the Bret Johnson website..
Anyway, I mean to say there's hope. 🙂

Edit:

the3dfxdude wrote on 2023-09-12, 03:01:

rasz_pl wrote on 2023-09-11, 21:03:

manufacturing flexibility, respin PCB design for the cheapest part of the week instead of being linked to one vendor and price/availability swings.

So we have a guy, who bought a _used_ book, finds he has a burned out XL4015, also has a different pcb than another person. And I'm to be told the independent guy doing this is already respinning and practicing DFM on what was announced as a hobby run, and so the issue is not coming from a defect? My suggestion would to be cautious and check over it some more instead of directly slapping another IC on there. Of course the previous owner could have trashed it doing something stupid. This thing is attracting tinkerers primarily so who knows.

Absolutely.

This reminds me of something loosely related, btw.

Rule number #1 - never buy something from a CB radio operator, it's likely broken.
Rule number #2 - if you did, check with a multimeter first, don't attach your equipment straightaway.

Same applies also to certain radio amateur folks who offload their junk onto you, masquerading it as a generous present (the waste disposal charges them money).

I'm speaking from experience here. Sadly.
- A family member of mine is both, so I don't hold a grudge against these people whatsoever. It's just an observation. 🤷‍♂️

Especially power supplies were affected, both lab psus (13,8v) and ordinary power bricks.

It's kind of funny if you measure voltages and find out that the "good" power supply
does suddenly output 25v instead of 13,8v (modded for a stronger linear amplifier or simply broken ?).

Or, if the 12V DC power brick for an auxiliary device (radio modem, rtty decoder) outputs 18v AC unregulated. No really, I've bern there.

As much as I love the hobby and enjoy wirking with people, it's better to be safe than sorry.

Jo22 wrote on 2023-09-12, 09:09:

Technically, it's possible for sure. There are vintage DOS mice drivers for real USB controllers, even. They worked with text-ba […]
Show full quote

Technically, it's possible for sure. There are vintage DOS mice drivers for real USB controllers, even.
They worked with text-based applications like Norton Commander and its clones (Volker's Commander etc).
There also were USB drivers on the Bret Johnson website..
Anyway, I mean to say there's hope. 🙂

Thanks, it would be nice to find barebones int 33h mouse driver source, so i won't have to write one from scratch, C source would be best as it might be too time consuming to write in assembly.
To be honest, i didn't do an extensive search for available mouse drivers with source, as my "bootable floppy emulator" is not quite finished yet. NASM needs 386 to work.
I've seen link to chinese code for interfacing HID via CH375 here on Vogons, so it should be possible

I had a feeling that there was source for a logitech mouse driver out there in the wild at some point.

n0p wrote on 2023-09-12, 08:40:

Now, mouse driver for CH375 chip, anyone?

https://github.com/joshuashaffer/book8088-ch375mouse-poc

rasz_pl wrote on 2023-09-13, 02:42:

https://github.com/joshuashaffer/book8088-ch375mouse-poc

Awesome, thanks!

betamax80 wrote on 2023-09-12, 23:03:

I had a feeling that there was source for a logitech mouse driver out there in the wild at some point.

That would be cool, because the Logitech one supports the Helix Multimedia Cloaking technology (running above 1 MB).
Sure, that's not really important on an XT, but might be of general interest for DOS users (USB code might be memory consuming, so it's nice if it can be made get out of the way).

Ok, here's my work on BIOS so far.
-
Very basic int 13h handler for CH375 chip:
Will work with floppy images, written to USB flash with Rufus or DD. Specs are read from boot (0) sector.
Should take any as long as heads <=2 and sectors>=8 and <=36
Media is always reported as 1.44MB, so format will produce this exact media regardless of previous boot sector settings.
Boots, checked 😀
MS-DOS 3.30 doesn't recognize XT-IDE drive, no idea why.
Inits only if flash drive is present on bios start. That's the way i wanted it to.
Fully replaces original floppy handler, so if flash drive not inserted, zero floppy drives reported.
Media change detection not implemented so far as i've no idea how the logic should work (ch375<->ms-dos).
To boot from "floppy" you need to press A (XT-IDE menu) after "floppy seek and beep" sound.
-
Previous changes there as well - two XT-IDE BIOSes, only one for inserted CPU inits.
It's not handy two swap two chips at once, and BIOS chip has not enough opening for quick replace.
You might always use 8088 version, but V20 version 1,6 times faster.
BIOS boot sound - speaker plays PWM with floppy seek and beep from real XT 😀
-
BTW, Sergey accepted both proposed fixes, so BIOS for Book8088 on his 8088_bios github works for 3-Demon and Turbo Basic now
-
Thanks to author of MartyPC - it's only emulator i know that allows easy BIOS placement, so i could test "Does it even init" without having to flash/test cycle on Book8088.
-
Will sync to github after commenting the code.

Very cool @n0p.

Do you think I should wait on the new version with I/O when it's available on a more "UK friendly" storefront, or do you think the original will be more widely supported?
(I'm wondering will there be a BIOS tweak supporting those new ports)

Serial/Parallel port support is already in Sergey's BIOS, so that shouldn't be a problem.
Have you tried writing to Ali merchant asking for fresh photos of Book8088?
They sometimes don't even care to update listing.
-
Being using Book8088 for some time now - my point stays, keyboard and screen are actually the worst thing about it. I started to really hate the keyboard after writing code on it. Screen centering problem is also very annoying. Not that my fingers are that big, but pressing Fn-F7 to issue "mode 80" command require much smaller ones, as it's not enough space between screen lid and upper buttons row.
-
Worth noting that "CGA" card made replaceable on new model

I will contact the "main seller" I think on AliExpress for news then. Ah I see so it's a board that can be replaced... that's promising.
Did I see a GUS module that looks like the OPL3 somewhere too?

n0p wrote on 2023-09-13, 18:55:

-
Thanks to author of MartyPC - it's only emulator i know that allows easy BIOS placement, so i could test "Does it even init" without having to flash/test cycle on Book8088.
-

Glad it's been helpful for you! Let me know if you have any suggestions for better rom handling.

betamax80 wrote on 2023-09-14, 23:41:

Did I see a GUS module that looks like the OPL3 somewhere too?

Might that be PicoGUS?

GloriousCow wrote on 2023-09-15, 12:13:

Glad it's been helpful for you! Let me know if you have any suggestions for better rom handling.

It's awesome as it is, thanks! Not flattering 😀
How do you personally find the Book8088?
-
Found out that MS-DOS 3.31 existed and supported 512MB drives.
Downgraded, but if you want to take that path - don't partition the drive, just format original one. I've so far didn't figure out why, but partitioning broke the logic of drive for XT-IDE and i couldn't make it bootable until i restored full backup.
3.31 chkdsk hates long-filename entries and deletes them (no actual damage), and label command reports "not enough space in root", but otherwise everything works, 585KB free RAM with CH375 DOS driver and Volkov Commander loaded.
-
Tested floppy emulation with CheckIt:
All good in normal mode
One or two write errors when in Turbo mode. As increasing delays on CH375 IO didn't help, i suggest it might be Book8088 problem itself on increased frequency.
Sources https://github.com/jinshin/8088_bios
3751.inc and 3752.inc
Hope it would be helpful for someone as i couldn't find any actual tech manual for the chip. Those from manufacturer are not useful.

I have emailed and tweeted about the version I/O and will update as I hear back.
I note ETA Prime has done a review now: https://www.youtube.com/watch?v=O70vLEEOLGM

A response from @pengan on X: "Pengan Zhou - "Develop a Tandy compatible graphic cards is more difficult than VGA because single-chip VGA solutions like CHIPS 65545 or TVGA9000 are very cheap and common on the Chinese electronics market (as well as Aliexpress). Tandy sound is feasible, but not planned currently."

I'm also advised that this AliExpress seller should be able to help me get the version with I/O: https://www.aliexpress.com/store/1102811598

UPDATE: DZT Store and "Hardcore Expert Store" tell me that the new version with Serial and Parallel will be available within a few days - one store told me it will also have the VGA interface at the same time (not sure if this will be optional or not).

Perhaps it would help if they implemented the Graphics Gremlin design in a newer version of the Book 8088, with proper attribution?

The design of the Graphics Gremlin has been released under an open-source license that permits commercial use.

The developer of the Graphics Gremlin has expressed an openness to adding Tandy 1000 and PCjr graphics compatibility to it in a future revision. Perhaps the Book 8088 developer(s) could even help with that. Much better than starting from scratch.

https://github.com/schlae/graphics-gremlin

VGA out would be quite nice, since where's already an unused 10-pin connector space with traces to it, just missing a few resistors.
12-pin connector to display board is like this:
1 5V
2 5V
3 5V
4 GND
5 H-SYNC (?)
6 V-SYNC (?)
7 GND
8 B
9 GND
10 G
11 GND
12 R
--
Alas, can't find this (12x1,25mm) connector locally, so test connecting a 8-inch IPS is postponed a bit

n0p wrote on 2023-09-17, 17:10:

VGA out would be quite nice, since where's already an unused 10-pin connector space with traces to it, just missing a few resist […]
Show full quote

VGA out would be quite nice, since where's already an unused 10-pin connector space with traces to it, just missing a few resistors.
12-pin connector to display board is like this:
1 5V
2 5V
3 5V
4 GND
5 H-SYNC (?)
6 V-SYNC (?)
7 GND
8 B
9 GND
10 G
11 GND
12 R
--
Alas, can't find this (12x1,25mm) connector locally, so test connecting a 8-inch IPS is postponed a bit

From what I understand the developer is already well along the way of adding VGA - it seems now that the model with parallel and serial will also ship with VGA. I'm not sure what the price will be yet - it's likely to add another £30-£40 looking at the different specs on AliExpress. I will attach the pictures from Pengan's X feed.

Sorry, i wasn't clear - i meant VGA 15 pin connector for external display.
--
As for Graphics Gremlin (thanks for pointing at that project!)- as it's based on programmable logic, just as Book8088 "CGA" - i might suggest that at least parts of that project are already there 😀