The A1200 Thread

[chrisgreen]

@RobA1200 It is indeed the Indivision Mk3.
Apparently the Mk3 is quite different. The biggest change being that it taps directly into the keyboard controller to intercept keypresses and allow for things like screen realignment, stretching, overscan etc (I think addressing the centring issue you mentioned). It is a shame though that this also has to fit over the top of the keyboard controller as well as the Lisa, as it means that if I decide that the wedge case is not for me after all and I want to go for a big-box Checkmate case and standalone keyboard (remember, I recased my original A1200 into a tower - twice!) I would have to lose the scandoubler in order to fit a Sum1200 USB keyboard controller.

I have not seen or heard of the Tsunami 1230 card. I had initially been hoping the Terriblefire 1230 was going to come to something, but Superduper told me in no uncertain terms not to hold my breath on that one, which is why I switched focus to saving up for the Vampire V4 080 card (rather than getting a Terriblefire 1260 and then crippling it with an LC chip because I'm not paying £300+ for a used full rev6 060). I've pinged the Tsunami people to log my interest in buying one.

Are you back on your feet yet? Are you coming to the club tomorrow?

 

[chrisgreen]

Another arrival this morning. A clock port RTC and temperature sensor, to keep tabs on the Lisa temperature once the scandoubler is clipped on.

 

[chrisgreen]

Also managed to pick up a job lot of 41 new, old stock DD floppy disks for a fiver on eBay. Given they came with labels and a big wad of individual floppy disk sized zip lock bags, I think this might be left over from someone’s days running a PD library, or game copying ring.

 

[RobA1200]

much better thanks. I'll be there - looking forward to it. going to fit the gdrom to my dreamcast.

the MK2cr was almost command line for adjustment - was a right pain and took a while to adjust. MK3 sounds better.

never seen that temperature clock port adaptor before - pretty cool.

 

[chrisgreen]

More deliveries today for the A1200 rebuild.

This IO port shield arrived from the Czech Republic. This tidies up the rear ports, allowing you to completely dispense with the lower RF shield as well as the upper shield.



As I am having my RF Modulator removed from the board, I opted for the version of this backplate with a VGA connector mount in the space where the RF Out would be. I’m actually fitting an HDMI socket there as I have one designed to fit into the same space (and hex post mounts) as a VGA port.

 

[chrisgreen]

Couple more small arrivals today. I had already ordered a new LED cluster (not knowing about the Bifrost Project) which came today. It’s got clear light pipes unlike the frosted ones on the Amiga’s factory LED cluster. But, I am going to order the Bifrost one because I want to customise the LED colours. I am 5.

I also got a packet of new hex posts. Yes, I know - perhaps the most dull item imaginable.

So I think I now have everything to crack on with doing the build. Apart from a recapped motherboard, which should hopefully be back in a couple of weeks.

 

[chrisgreen]

Had a bit of spare time this afternoon so I started assembling the A1200 into the new transparent case. This was mostly to check the fit and finish of the case, the new shielding backplate, new indicator lights etc.

Pleased to say that the fit and finish of the A1200.net transparent case is excellent, as is the metal backplate I am using in place of the original RF shielding. Not happy with the new case indicator light unit I bought from Centuriontech. It works great and is made well. It just looks poor as the single LED in each position doesn’t fill each light pipe properly. So will revert back to the original lights until I get something from the Bifrost project (thanks again Rob for the tip on that).

Today’s initial build also gave me a chance to work on positioning some case lighting as well, as you can see in this video:

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[mikeitstop]

I expect the lights will be more diffused once you've painted that case beige.

 

[chrisgreen]

Never!

The lights seem more harsh in the video due to the iPhone camera not coping so well with it. Better to see it in the flesh next week.

 

[chrisgreen]

Been a while since I posted an update as I've been up to my neck in work. Got one of my motherboards (the 1D4) back from RetroPassion, who did a recap and ultrasonic board clean. Went with solid polymer caps, so all being well these will be good for the foreseeable future.



You will see that Kickstart 3.2 ROMs have already been fitted to the board. The RF modulator has also been removed. Apart from the fact it's really not much use in 2021, that space is where I will be mounting the HDMI output for the scandoubler.



This HDMI male to female cable is quite handy, as the screw posts are in the exact same positions as the hex posts on a VGA socket, so will fit into the VGA socket-sized hole in the backplate from my earlier post. Also, the new A1200.net cases have a VGA port sized hole instead of the oval hole where the modulator used to be.

 

[Retro]

The RF modulator has also been removed.

This reminds me, many, many moons ago, I managed to get the PC video output connected to a modulator and the TV. Terrible picture of course, but when I played Half-Life 2, it had a real "arcade videogame" feel to it and was in some ways more enjoyable than playing it at the usual high resolution. The way the colours and textures were smoothed out, the dot crawl and CRT look all added to the effect. Alas, I no longer have the hardware to repeat this experiment.

 

[chrisgreen]

RF modulators in modern LCD TVs are often terrible (and not very sensitive, unlike those found in most CRTs, making the process of tuning on a moderate signal even more challenging). I have tried running both the Amiga and some of my Speccys via RF on a modern telly, the experience is not fun. Made the decision to have the modulator removed that bit easier. Also have no CRTs left (and no intention to buy any), so focusing on getting the most clear, ghost-free digital or RGB image I can out of the machines. For the main A1200 build, I'm going to fit the Indivision AGA Mk3 scandoubler, which will give me a pretty decent HDMI output (with sound). For the backup board (simply because once a Scandoubler is clamped on to a board, I really don't want to try and remove it - bad things happen to PCBs when you try that), I'm thinking about fitting a cheaper Scanplus AGA scandoubler (which does not flickerfix like the Indivision). That has a VGA output so won't be as good as the Mk3, but will at least provide an option for direct connection to a modern monitor without needing additional hardware.

After RetCon, when hopefully I can find some time, I'll be sending the other board off for recapping (going to do the polymer caps on that too), given I can't be sure if the caps on it are original or new - they look new, but god knows - the RF modulator will also be coming off of that one.

 

[chrisgreen]

A couple of new arrivals for the Amiga build:

Custom made buffered RGB to VGA adapter.







As 23-pin connectors are no longer being made and the remaining stock is an arm and a leg, most people are taking a standard 25pin connector and cutting two pins off one end. It works, but does result in a lop-sided plug. For example, if you buy an Amiga RGB to Scart lead today from RetroComputerShack or CoolNovelties today, they are both using cut connectors. They work absolutely fine, but the lop-sided fit means it overlaps the composite video connector on an A1200.

The solution here, a completely 3D-printed 23-pin connector. Fits and works well. I particularly like that this has both the screws to attach it to the Amiga, and the Hex posts on the VGA port. Most of the other examples of this adapter don't have any of the securing fixings.

Hex Posts.



Not exactly an exciting thing, but given I've had to remove all the original ones to remove the motherboards from their RF shielding and original cases, I thought it would be a good idea to refresh them with new ones with fresh threads. Also, on one of the motherboards, it actually had some odd posts (so clearly some had unscrewed in the past, been lost and replaced with random PC parts). Here I have two dozen new, matching posts to be refitted to both boards along with their new metal backplates (see previous post).

 

[mikeitstop]

Custom made buffered RGB to VGA adapter.

View attachment 286
As 23-pin connectors are no longer being made and the remaining stock is an arm and a leg, most people are taking a standard 25pin connector and cutting two pins off one end. It works, but does result in a lop-sided plug. For example, if you buy an Amiga RGB to Scart lead today from RetroComputerShack or CoolNovelties today, they are both using cut connectors. They work absolutely fine, but the lop-sided fit means it overlaps the composite video connector on an A1200.

The solution here, a completely 3D-printed 23-pin connector. Fits and works well. I particularly like that this has both the screws to attach it to the Amiga, and the Hex posts on the VGA port. Most of the other examples of this adapter don't have any of the securing fixings.

A nice example of how 3D printing is superb for niche demands

 

[chrisgreen]

I've had this for a while, but realise I've not actually posted any pics or info about it. This is the Wicher 1211 Memory and Expansion card from 7-Bit. Costing only slightly more than an ordinary 8MB RAM Expansion, it offers quite a bit more functionality that is needed for productive Amiga use in 2021.



It comes in two parts: The tradition trapdoor memory card, along with a second board connected via a ribbon cable that contains both an Ethernet port and a MicroSD card slot. The second board is designed to sit in the rear trapdoor position, which I have the .stl file for printing the mount, though it's proving harder than I expected to print it well as it's very small.

The RAM expansion contains 16MB of RAM, of which 11.5MB is available to the Amiga as Fast Ram. A further 1.5MB can also be used as a battery backed up ROM space that will boot in place of the system Kickstart ROMs, so handy for trying out custom Kickstart builds. The upper 4MB can be disabled either with a jumper or through software to allow for PCMCIA card slot functionality.

Software is supplied in the form of drivers for the Ethernet and SD Card hardware, as well as a utility for managing the RAM and mounting/unmounting the SD Card.

I will be using this card until the Vampire V4 1200 comes out in Q1 2022, at which point I will be upgrading and this will be moved to the back-up system.

 

[chrisgreen]

I got the 1D1 motherboard back from recapping by Retro Passion. So now both 1200 boards are clean, recapped and ready to go.

On paper, the 1D1 board should be the more stable/reliable one. So I am likely to use that as the board in the clear A1200 case.



One thing that did turn up this week was a new accelerator card. I still intend to get a Vampire V4 Ice Drake next year when it goes on sale, but until then the 1200 could do with a bit more oomph than a Fast Ram expansion alone produces.



This is a TerribleFire TF1230. A low cost, newly developed 030 accelerator. With 64MB of fast ram, a high speed IDE header and a 50Mhz 030 - it does quite a bit for just £120.

My one actually has a 33Mhz black top 030 overclocked to 50Mhz. This is fine, the black ones are cheaper and happier being overclocked than the gold-top ones. It gets a little warm, but nothing to worry about.



The card has been given an initial soak test on the 1D1 board and both the computer and the accelerator are performing well.

Still to test is the IDE controller on the TF1230. My plan is to run a second CF card on this, mounted on the rear trapdoor. Assuming it works.

 

[Tygerboi]

More deliveries today for the A1200 rebuild.

This IO port shield arrived from the Czech Republic. This tidies up the rear ports, allowing you to completely dispense with the lower RF shield as well as the upper shield.

View attachment 246
View attachment 247
As I am having my RF Modulator removed from the board, I opted for the version of this backplate with a VGA connector mount in the space where the RF Out would be. I’m actually fitting an HDMI socket there as I have one designed to fit into the same space (and hex post mounts) as a VGA port.

Please can I ask where you got hold of the HDMI socket that fits into the same space and hex mount posts as the VGA port? Or is that supplied with the Indivision MK3 scandoubler? Did you also obtain a plastic case cover with a VGA socket cutout that fits in the old modulator hole so that the case still looks neat (presumably such a thing could be 3D-printed)?

 

[Retro]

@Tygerboi welcome to NerdZone Forums. Glad to have you with us.