Does anyone have any idea how to get the AdLib fired up on the PC side in either DOS or Windows 3.11 (WFW)? I feel like I've hit a brick wall trying to work out what I am doing wrong, or maybe I have no idea what I am doing :smile-new: How do you enable to AdLib to do things? In DOS I've had no luck getting any sound but PC speaker... On the Mega Drive side the sound is working perfectly. I've had a tinker with the Jukebox software (version 1.64) and the test.exe file and they both report "Adlib board not found!". Disabled resources in BIOS, tried switching the IRQ on the Mega Drive ISA card with no change. Any ideas? :dejection:
Yikes! I posted this seven hours ago? That means I've been working on this for... I don't even want to think about it! Progress report (or lack of) follows... 1. Distorted sound through the Mega Drive ISA card. Tested with Monkey Island 1 with the switch "monkey a" for AdLib sound. Tested with Paku Paku 1.6 from here with the switch "paku /adlib" for AdLib sound. Both games give distorted / inaccurate sound - I'll edit this post and add a video later on. 2. Correct sound through a Creative Sound Blaster CT1350 (Rev 0) with the Mega Drive ISA card removed and PC jumpers enabled. I suspect all my Sound Blaster cards will work with the Mega Drive ISA card removed, which is bad. I've tried different Hex, IRQ, DMA, etc settings to no avail with the Mega Drive ISA card installed. The Sound Blaster card just worked first time after being connected, didn't need to set any variables either. I guess my next step could be any of these; 1. Give up on advanced AdLib sound on the PC side and stick with speaker beeps 2. Play around with jumpers on the 486SLC motherboard 3. Mess around with the ribbon cable connecting to the motherboard from the Mega Drive ISA card 4. Keep waiting for anyone else who might have a bit more knowledge on AdLib based sound cards in Mega PCs... The only thing that I can think of that might be causing the issue is the 486SLC motherboard I installed in place of the 386SX motherboard. I've tried disabling some even more obscure settings in the BIOS than I ever knew existed with no success. Ideally if someone has a Mega PC out there and can test the Paku Paku game above with their machine, I'd be interested to know if the sound is perfect :smile-new: But if anyone has any ideas at all, please do post them as I am pretty much grasping at straws... :dejection:
I wish I could tell you something about the AdLib sound but I haven't really done much with it. I only played a bit of Wolfenstein 3D and it had some nice FM tunes. It was preinstalled by the guy who sold me the Mega PC so unfortunately I can't say anything about settings.
What do you mean by "486slc motherboard" ? you replaced the whole mobo? did they made a 486slc-based mobo for the MegaPC? If you replaced the whole mobo maybe there is some sort of design change and thus an incompatibility? Or you put a 486slc upgrade on top of the 386sx? In that case I doubt it will be the problem. Only had a non-working megapc once , sadly I can't be of more help
Yes keropi there are 486SLC boards for the Mega PC. Normally they would be in the Mega PC Plus and are mostly identical to the 386SX board so they shouldn't cause the issue with the AdLib part, they are meant to work together after all. There might be something on the board that has to be jumpered correctly, that's basically all that's left if the IRQ jumpers on the ISA card didn't do anything.
The board I have installed currently is a whole replacement for the 386SX board. Here's some photos of the machine (Amstrad PC7486SLC) it came out of, note the similarities and differences to the Mega PC 386SX we all know and love. Now here's where it gets interesting; The original 386SX board from my Mega PC The same design board but with a 486SLC board (found on the web somewhere) And lastly the board I stuck in from the Amstrad PC7486SLC Now given that mine isn't the same as the 486SLC, yet shares similarities with it may be a coincidence, or there may have been a third revision of the 486 version of that was either canned or an updated Mega Drive ISA card... so many possibilities! I'll give Wolfenstein 3D a go though and see if anything good comes of it!
And the YM3812 roars to life with the theme of Monkey Island! Found that sound was working well through the 3.5mm socket without the rear plate installed. So I jiggled the card and found that the sound would cut out and go blocky. Bad connection perhaps? No! Cleaned all the contacts and reinstalled, same issue. Came so close too. I had all the parts on except for the case cover screws. Put them in and sound was lost / distorted again. Then I got thinking, the alignment of the motherboard, ISA card riser, front panel board... all could be misaligned in some one. All because I took it apart when I first got it and tinkered with the insides. That said, I hadn't tested the PC sound side until now. Pulled everything out of the machine and started again. Aligned the motherboard closer to the front of the machine. After meticulously piecing it back together turning it on and testing after each screw went in, we have a victory. Amazing how I created an issue for myself months ago accidentally to keep myself busy for the entire weekend! What was I thinking, I could have spent the weekend... well working on another retro device! Better get MS-DOS 6.22 and Windows 3.11 installed again - Hopefully with sound this time... :encouragement: This means there are definitely at least three compatible boards with the Mega PC design! I'll put some videos up here once they are edited and uploaded. Sure is interesting to watch the progression of determining the cause... :encouragement: Thanks for reading and your input everyone! Edit: Smoke and Mirrors Alright, no mirrors here, but definitely smoke! The hard drive decided to pack it in as I was attempting to install DOS. The machine just powered off while booting to the DOS 6.22 floppy... no response when flicking the power switch. Went and pulled out the PicoPSU and hooked it in and it powered on... few seconds later... smoke! 107MB drive removed and pending repair, 503MB drive installed and installing DOS... Talk about trouble! Glad it wasn't the mainboard as I just realised I haven't noted down the capacitor values on it as of yet. And this is exactly why I photograph things, so I can see what their values were when they do eventually go up in flames! Markings were 156 25V, 15uF 25V right?
I have looked at the mobo pics you posted, you say you are using the the Amstrad PC7486SLC motherboard? There is no CON15 at the upper left on that, instead there is a jumper block...? does the slide door switches video outputs between pc and md?
Yes! That's the beauty, with the jumpers in place, you don't need the Mega Drive section or the switches. It just becomes a regular old PC. Remove the jumpers and install the Mega Drive ISA card and you can use the switch on the front of the computer instead. The jumpers just act as a bypass for the switch on the front when configured as a PC only - great for diagnostics on the PC side I might add! You can add the jumpers in this configuration onto any Mega PC without a Mega Drive ISA card installed and you'll get PC video out the VGA socket. If you don't put the jumpers on... you just get a blank screen! I only found out about this as this board I ordered already had the jumpers on it as it was a PC only machine. So I learnt something there too! :biggrin-new: Edit: Here's a picture of my old 386SX board with the jumpers on for comparison.
just connect another old IDE drive and use OnTrack Disk Manager to fully access it since the BIOS will be limited to 540MB most likely... I use 20 and 40GB drives on my 386 machines with Disk Manager
What do you do with all that free space though? Even with a 500MB installed instead of the 100MB one... Windows 3.11 just doesn't use enough of it :biggrin-new: I haven't had the need to go above and use my larger drives... yet. I think I've got a 10GB one put aside for some XTIDE cards in the Sega TeraDrives. I am very curious on how that goes, cards are on the way and due either this week or next!
Why not?!?! My hard drive will just catch fire again... hahaha! Actually that is a very valid point given I want to give Sam & Max: Hit The Road a spin. It's going to be hard deciding which computer to play it on though. I do like the odds of it being played on my Osborne 486 It hasn't got any fancy Mega Drive built into it... but it does have a 2x CD-ROM! And I recently stuck a 5.25" floppy drive in the front as well. I think this only has a 300MB drive in it too (original from what I can tell). The quest for more storage... or the quest to keep it in original condition as long as possible...
