Reply 60 of 95, by keropi
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- l33t++
damn these pics ... the last one is a real drooler with the monitor/kb 😁
damn these pics ... the last one is a real drooler with the monitor/kb 😁
Thanks, it cleaned up OK! I have found baby wipes to work well. Our house is full of them 🤣
So over the weekend I mounted the CF card/microdrive in the lower half-height bay and added an IDE activity LED in the front panel (IDE pin 39).
Encouraged by my success, and waiting for a floppy controller & 8087 to come in before I put the lid on this puppy, I went a bit mad and ordered a PCB and parts for the Lo-tech 2MB EMS board. https://www.lo-tech.co.uk/wiki/Lo-tech_2MB_EMS_Board.
We shall see whether I can solder the SMT parts by hand or just make a horrible mess and chuck the lot in the bin!
Great!!! What things use ems on a xt ?
Non-games stuff... Lotus 123, Programming languages, PKZIP. Alternatively can load up to 64kb of drivers in upper memory.
really nice , that ega PoP screen is great!
Looks good eh! Shame it is way too slow to play 🤣
I am finding out the 8088 experience is a lot about thinking "wow this is slow". Really only the very earliest games are fun, and I guess slower-paced RPGs etc would be fine too. For me these machines are more about the tactile experience, flipping the big power switch, using the keyboard, the way the phosphor on the 5153 looks. A turbo XT would be a lot more usable for games.
I can recommend the Video 7 VEGA though, I'm finding that with the CGA compatibility TSR installed it works with pretty much everything, even the 160x100 16-colour mode. 8088 mph screws up it unsurprisingly 😀
Jim Leonard/Trixter has an awesome collection of games & utils specifically intended for PC/XT & CGA machines at ftp://ftp.oldskool.org/pub/misc/xtfiles.rar. This is ~100MB of hand picked goodness and a good use of a larger hard drive.
I do like the way the system looks though. With all the interest in retro interior design these days I could see some people putting it in their living room.
Too slow eh? I haven't tested any "advanced" games on my XT, I will have first hand experience once I install a XTIDE card. That "base xt installation" is already downloaded, this is what I plan to transfer to my HDD when I'll be able to use it 😀
I take it that the V20 didn't improve things much in your setup... isn't there a hack/mod/way to add a dual-clock like the turbo xt clones? I guess it will be complicated but it would worth the trouble IMHO.
Did you ever post a pic of the VEGA card you use? They used the name in various cards AFAIK, it would be nice to know what to look for 😉
The 5160 does look really great 😊
wrote:8088 mph screws up it unsurprisingly 😀
One issue is that 320x200 mode is 70 Hz on a VGA monitor, and 60 Hz on CGA/EGA.
Did you try CGADEMO? http://www.pouet.net/prod.php?which=64406
On my Paradise VGA card, it does something quite strange...That is, the rasterbars are done by polling the display_enable bit, which should be a good approximation of when it goes into horizontal blank interval. Now, if the timing was just based off 70 Hz scanlines instead of 60 Hz, it would work just fine, only slightly faster (that's basically what you'd do in VGA mode).
But instead, what it looks like is that the display_enable bit is simulated at CGA-speed, so 60 Hz, while the display updates at 70 Hz, so the rasterbars stretch out vertically, and shift horizontally in weird ways.
Yep I tried CGADEMO. Although it ran, the raster bars filled the height of the screen and I thought my monitor might explode 😎
The VEGA is an EGA card so 320x200 should still be 60Hz.
wrote:The VEGA is an EGA card so 320x200 should still be 60Hz.
Oh right, for some reason I keep thinking that VEGA is VGA 😀
But yes, then it's even more weird that it would screw up.
Maybe the V20's throwing it out, or the VEGA's CGA compatibility mode isn't 100%.
On another note played Paku Paku last night, it really rocks with Adlib and a gamepad! It has great PC speaker sound too.
Also installed Deskmate, works OK with 640x200x16 but really slow. Just having a blast trying different software from Trixter's XT archive.
wrote:Maybe the V20's throwing it out, or the VEGA's CGA compatibility mode isn't 100%.
CGADEMO is not time-critical, it works by polling, so it will work on any CPU speed. So the problem is probably that the polling of the CRTC status register yields strange results in the CGA compatibility mode.
nice!!!!
I also have a 8087 laying around, don't think I'll install it though - same as having a 287/387 IMHO , almost useless 🤣
So now you have V20/EMS/FPU... what's next planned for the machine? 😀
High density floppy controller is due in this week, then I'm done I reckon.
Was having some problems with hangs when using the XT+ version of the IDE-CF bios, but changing to an 80-conductor IDE cable fixed that.
The XT+ bios does speed up disk access noticeably. Another thing that helped a lot to speed up screen refresh was using the N_CGA version of NNANSI in Trixter's XT archive.
interesting tip about the 80-wire cable , I will be using a CF with the fully fledged IDEXT rev2 board... the XT+ version is the one with the speed hack , right?
Last piece of the puzzle in place... HD floppy controller + bidirectional parallel and 16550-based serial port.
Shots of the final internal layout
Not 100% plain sailing of course... Carlos' HD floppy bios detects the Gotek as 720k, not 1.44MB.
It also causes the 360k drive to make horrible screeching sounds during drive detection 😒
2M-XBIOS works though, so I think the hardware is OK. I may try some other HD floppy bios.
Also, with the Winbond FDC, I get an intermittent 601 (FDC) error at POST. It still works after boot.
The 360k is awfully noisy when moving the heads and I think perhaps it would benefit from a good clean and greasing the rails.
The 601 error may be from the head taking too long to do the full track seek.