Book 8088 discovery and modification thread

[sergey]

Regarding the potential logic level issues, I have an RTL8019 ethernet card running in the ISA expander. Its ASIC must be compliant with the HC series logic. If anyone is having trouble with ethernet cards, I can vouch that the 8019 works in my unit. Ethernet has been really handy to move files back and forth to a windows computer running an FTP service. I'm using mTCP.

Most newer LSI ICs are CMOS, that includes RTL8019AS Ethernet controller, various VGA controllers, etc. And they will have CMOS level outputs - very close to VCC == 5V for logic "1", that would work just fine with 74HC.
The problem will likely happen when TTL or NMOS outputs are connected to 74HC inputs on the Book8088 board. That includes ICs like 74LS245 that are often used to buffer the data bus on ISA cards, including some newer ISA cards.

 

[sorphin]

and.... nope on all fronts.

 

[sorphin]

That's for COM/LPT ports i think, since it looks like they bolted to the case in V2

So it appears (I just flipped my v2 over again and sure enough.. seperate board... though 40 pins for 25+9... 6 pins doing nothing? unless there's actual circuitry on the daughterboard and those are supplying power and something else.. (I haven't taken this apart as much as you have yet.. Don't want to break it (yet). lol

 

[n0p]

So it appears (I just flipped my v2 over again and sure enough.. seperate board... though 40 pins for 25+9... 6 pins doing nothing? unless there's actual circuitry on the daughterboard and those are supplying power and something else.. (I haven't taken this apart as much as you have yet.. Don't want to break it (yet). lol

Just be careful with female audio connector - from what i see on V2 photos it would be much harder to fix if it falls off than in V1 - traces are very short and goes to other side of board right away. After fixing mine i've shoved off about a 1mm from it, so now assemble/disassemble is much simpler.
I'm absolutely stopped thinking about getting V2 after looking at board photos. Display connector gone, board overall looks like designed in hurry - have you seen traces to CH375 chip? Might order one from taobao directly while V1 is still available - just to have a replacement one if i break mine.
For me it's great idea badly executed, hope we will see an XT this small and functional but done right some day.
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Desolder gun - would you recommend decent cheap one for home, not professional use?
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Fun, i've remembered that my XT (Poisk-1) had RGB out i plugged into TV directly - and i switched G and B sometimes to have alternate palette in games.
Since i still waiting for thin wire to arrive, and there's jumper wire connectors to ext screen anyway, i might do that mod too for V1
VGA actually allows this w/o hardware mods - you can program it's pallette registers to any colors after setting CGA mode. Found some of my old unfinished work on that.

 

[sorphin]

I'm absolutely stopped thinking about getting V2 after looking at board photos. Display connector gone, board overall looks like designed in hurry - have you seen traces to CH375 chip? Might order one from taobao directly while V1 is still available - just to have a replacement one if i break mine.

I wanted a v2 because of the ports and the socketed video card. I have no intention to do the video mod you did, so i'm fine with no display connector. tbh, the only mod that interests me are probably the adding UMB (presuming the CPLD bit can get sorted out).. I still have plenty of kynar wire left on my small original spool, even after all the years of mods i've done.

Desolder gun - would you recommend decent cheap one for home, not professional use?

Get the Hakko FR-301... I was unsure at first (I've been soldering since the late 80s), and the price compared to braid or the stupid plunger things.. now I wish I'd had it years and years ago! I've removed things with it that I wouldn't have screwed up if I'd had it instead of using braid.. the only time I don't use it now actually, is when low temp solder (i.e. chipquik) will do the job faster because i don't care about the part (or, it's SMT and you can't use a desoldering gun). The Hakko might not fit your definition of cheap, but once you get using it, you'll wonder why you didn't have it years ago.. it's already 'paid for itself' in my own mine with TIME/boards saved.

 

[GizMo79]

Sorry for the question, do you know a text editor that works when I'm connected in serial with ctty?

 

[Betamax80]

I posted my opinion at Vogons. IMHO TVGA9000i is a better fit for 8088-based system, just because its BIOS doesn't use 186+ instructions, so it will work with the 8088 processor.
I think TVGA9000i is more rare/expensive at this time, so that is the reason they didn't use it.
Another reason mentioned in Twitter, is that somehow Trident VGA BIOS has a copyright... And the makers of Book8088 try to avoid copyright issues. The truth is that both Cirrus Logic and Trident VGA BIOS extensions have a copyright, and both based on the code developed by Quadtel. It is just Trident VGA shows a splash screen for a few seconds when booting, while Cirrus Logic simply prints a copyright message and continues booting, so if screen is quickly erased after VGA BIOS extension initialization, users might not notice that copyright message.

So here is a question for the current owners of Book8088 V2: Can you post a screenshot or a video of the Book8088 POST? Do you see something like:
CL-GD5422/5424/5426/5428 VGA BIOS Version 1.30
Copyright 1992-1993 Cirrus Logic, Inc. All Rights Reserved.
Copyright 1987-1990 Quadtel Corp. All Rights Reserved.
07/08/93

I've owned an old PC with Cirrus BIOS so I know what you are referring to,
But I can confirm you don't see anything, screen remains dark until actual BIOS starts up - in the case of Serhii's only when you the "banner" for his BIOS.

 

[Betamax80]

That's for COM/LPT ports i think, since it looks like they bolted to the case in V2

I can confirm they are attached directly to the plastic casing by the screw terminals.

 

[n0p]

Not exactly a serious mod, but as a part of learning microsoldering i've replaced Book's indicator leds - wanted to do that from the start. Left blue "full charge" one, but might replace it with green as well. 0603 doable with magnifier and thin tip.
Now CF is green, turbo - white, "alive" - yellow

 

[n0p]

Soooo
First proof of concept - keyboard connected

 

[n0p]

Unfortunately, doing second part (connecting Waveshare Zero to controller chip "BK82C42") i did something wrong and chip died.
Don't know exactly how (even if there was a short, it would be short between signal lines), as i previously connected Pico to it's lines without problems.
Anyway i asked the seller if i can buy the chip (preferrably two ) and Book is working with external keyboard now.
@Retroplayer: any luck with getting firmware?

 

[kirikl]

I'm happy to report that the SDLPT works really nicely - the driver seems efficient.
I got my version from "curtis electronics" in the UK. Is uses the NC100SD driver.=

I still really want to know if this requires any special key to work? Or just device=sddrv.sys?
none of XT laptops, including book 8088 reacting on SDLPT. 486+ laptops are fine, XT tower is fine too, but I don't need this device there.

 

[kirikl]

Is it possible to make another sound card, like simple sound blaster to have another option for book 8088, other than AdLib or this port is dedicated to AdLib only?
I know about PicoGUS project (60pin edition)

 

[sergey]

Is it possible to make another sound card, like simple sound blaster to have another option for book 8088, other than AdLib or this port is dedicated to AdLib only?
I know about PicoGUS project (60pin edition)

Potentially... But will require some mods. At least for the V1, the chip select was generated specifically for OPL2 (388h). Sound blaster or compatible will need also other chip selects... So it will need some bodge wires to address lines.

 

[n0p]

OK, reworked keyboard code as it appeared that my first approach produced sticky keys sometimes. Now it looks good enough to show

BookKbd/book_kbd.c at master · jinshin/BookKbd

Project to connect external keyboard to Book8088. Contribute to jinshin/BookKbd development by creating an account on GitHub.

github.com

Uses FIFO buffer and fixed main loop.

So if someone wants to do the mod:
You'll need a lot of patience and thin wire (i've used AWG36, and it's really easy to break. But it's coating doesn't burn at 360C, that's great)
On a photo with Waveshare Zero close-up you'll see cut trace with soldered white wire - that's IRQ1 line.
There was only 6 colors of wire available, so Red is bit 2 for reference.

As a side note: Book works when 5V connected to it's 5V line, so if you insert a power source to Zero, Book starts to work

I didn't find C code to work with Zero led (i wish there could be just simple green one, not a fancy rgb, like on original Pico), so no indication for connected keyboard right now.

Other notes: video memory chip starts to fail sometimes, maybe it's static electricity.
Seller sent me a replacement chip, this time i think i should use resistors to connect lines. I plan to power it from Zero 3.3V line to make things simpler.
I just wish where would be a small RP2040 device with enough lines to connect internal keyboard to it.

Main point - i can now play Loderunner on my Book

 

[Betamax80]

I still really want to know if this requires any special key to work? Or just device=sddrv.sys?
none of XT laptops, including book 8088 reacting on SDLPT. 486+ laptops are fine, XT tower is fine too, but I don't need this device there.

Nothing special, device=sddrv.sys in config.sys and it autodetected.

 

[kirikl]

Nothing special, device=sddrv.sys in config.sys and it autodetected.

Interesting. Never worked on any of my XT laptops... Will investigate more. Neither with other driver though....
Failed to initialize card.
Same card and adapter on Compaq LTE Elite 486 laptop or LTE 5000 no problem. As I mentioned XT tower PC as well no problem...

 

[kirikl]

Is it possible to find better quality keyboard?

 

[n0p]

Coudn't help myself, ordered V2 with VGA and CGA cards, discount was too good, same price as if i order it from TaoBao.

Is it possible to find better quality keyboard?

Nope so far

Interesting. Never worked on any of my XT laptops... Will investigate more. Neither with other driver though....
Failed to initialize card.
Same card and adapter on Compaq LTE Elite 486 laptop or LTE 5000 no problem. As I mentioned XT tower PC as well no problem...

I suggest reseating/cleaning XT-IO chip (big black CPLD Altera chip) could help the issue. Otherwise i'd contact seller

 

[Betamax80]

I think I've mentioned before but there is a jumper on the SDLPT, for selecting between the drivers in hardware - I don't know what it does as this version is closed source.