RetroChallenge - 2018/04 - Day 30

Well here we are again at the end of RetroChallenge and as usual I've done very little.
Here are the things I've actually managed to do over the month...

VideoNula

I tried installing the VideoNula board at the last ABUG meeting. Daniel kindly unsoldered the old video chip and added the socket to the board ready for the VideoNula to be installed.
Upon taking it out of its box I found that it was missing a pin. Luckily I managed to see the creator of this great bit of kit at the Wakefield show and managed to get a new one sorted.

Upon installing the VideoNula board I found that my PiTubeDirect overlapped into the space where the new board sat. To sort this I had to order some longer pin extensions which I added to the current pins to raise it above the VideNula board so that I can have both fitted.

Here they are both playing nicely together. The long board with a Pi Zero attached to it is the PiTubeDirect. Underneath that is the VideoNula board replacing the original video ULA chip.

The VideoNula allows for the palette to be selected from 4096 colours and supports hardware scrolling and various other extras.

PiTubeDirect

The PiTubeDirect is a board that connects a Pi Zero to the Acorn tube interface (by running special software on the Pi) and emulates various co-processors that you could get for use with the BBC.
By running a certain command you can change to various different setups.

The co-processors supported are...

65C102 running at 274Mhz (nearly 100 times as fast as the actual hardware co-processor)
65C102 running at 3Mhz (same as the original co-processor for compatibility)
Z80 
80286
6809
ARM2
32016
Native ARM (this runs on the actual Pi at 1Ghz)

By switching these on you can run code on a different platform and the BBC handles all IO.

Ethernet / MultiOS

I re-installed the Ethernet adapter from Sprow. This is a great item that sits in the machines Econet slow and provides modern networking. It provides the LanManFS filing system which lets you use a Windows share as a filesystem on the BBC.

Below the Ethernet card is the MultiOS board. This allows me to select various different OS versions by turning a switch on the back of the machine. I normally run in OS 3.5 but you can run the basic BBC 1.2 OS which allows for maximum compatibility. I need to create some OS images and get them burnt to the ROM so that I can change from the DataCentre (which requires a patched OS) to the BeebSCSI & GoTek floppy emulator (which works with the standard OS).

BeebSCI and VFS Adapter

I've already got a few of the BeebSCSI mini boards that allow the use of an SD card to provide a SCSI file system which is accessible from ADFS.

The DataCentre provides a similar thing but requires a patched version of ADFS to handle IDE drives. BeebSCSI works without needing to change anything on the machine.

As part of this project you can emulate a VFS drive (the laserdisc filing system that the Domesday project used). The final objective is to emulate the entire Domesday system without needing the laserdiscs or SCSI interface. 

Other Stuff

I started working out where the other interfaces I have will live inside the case.

Here are the DataCentre, BeebOPL (music synth) and the BeebSCSI mini. All run from the 1Mhz bus so I need to be able to switch between the DataCentre and the BeebSCSI easily.

I've got all the cables and connections ready just need to find the time to actually measure and make the cables to size.

My other external Co-Pro emulator, this is a different project but related to the PiTubeDirect.
This however uses a CPLD to do the heavy lifting. 

It can emulate the following...

65C102 (at various speeds)
Z80 (at various speeds)
80286
6809
68000
PDP11
ARM 2
32016

I am looking to attach this to the external Tube port so that I can switch between the internal PiTubeDirect and this.

Battery Backed RAM Cartridge

I bought this a while ago and it allows for loading of 2 ROM images which are stored in battery backed RAM so can be re-programmed from the machine. By changing the switches you get 4 different banks of 2 ROM slots. You can also use a real ROM and activate that by changing a switch.

External DataCentre

This is my external DataCentre.

It will be replaced by the internal one on this machine once the cabling is complete.
The unit allows you to load disk images from a USB stick and provides 2 IDE hard disk slots on the back.

Here is the re-assembled machine. Next stop a new paint job.

Anyway that's my (pretty lame) effort this time round.
See you back in the Autumn.

 

RetroChallenge - 2018/04

2018/04 RetroChallenge...

Well I'm already a week in and haven't even managed to have time to actually decide on a project this time round.

Pimped Out Master

I have several new bits of kit to potentially add to the BBC, my intention is to actually get round to doing the mods required and painting the case black.

So things that ideally need to be fitted...

VideoNuLA

This is a nice replacement board for the video ULA that allow the BBC to use and of 4096 colours in its pallet.
The kit also allows for hardware scrolling.

This is pretty straight forward to fit but I had an issue with one of the pins missing on the chip.
I've spoken to the guy who makes them and he's attending the Risc OS show this month so i'll take it along and see if he can sort it.
Apparently he's also added support for a BBC spectrum emulator so that the VideoNuLA can display the screen like the original spectrum.

DataCentre / BeebSCSI

I originally was going to have the DataCentre installed internally (which I may still do) but have recently got a new SCSI emulation card that allows the use of a SD card to be used as a hard disk.
I'm considering combining this with the GoTek floppy emulator which has a custom firmware that is pretty good.
I may connect this externally or perhaps install it inside the Beeb and connect the Wifi SD card / USB to allow remote loading of disk images.

Paint Job

Back at the last RetroChallenge I mentioned that I have some nice Vinyl paints that I want to customise the machine with.
The intention is to give it a black finish with a white BBC owl logo across the top.

Video Conversion Board

I have a VGA conversion board an would like to mount it inside with the VGA port accessible externally so that the Beeb can be plugged directly into a modern monitor.

Case Clips

As this is my main BBC and it will often require tinkering inside or maintenance then I'd like to put some kind of easy to open catches on the case.
The idea being that I can leave the screws out of the bottom to allow the top of the case to be opened (this is what it normally is like anyway) but be able to clip the top on to carry it.

Retro Challenge - 2017/10

2017/10 RetroChallenge...

Well work is probably going to get in the way of this months RetroChallenge, so I''m not aiming too high with my project this time round.

Pimped Out Master

I currently have a BBC Master on my desk but I'd like to fully pimp the machine out.

It uses an external DataCentre at the moment but I bought an internal one which I want to fit properly, I also have various other expansion cards etc that need to be fitted.

Back at the last RetroChallenge I mentioned that I have some nice Vinyl paints that I want to customise the machine with. The intention is to give it a black finish with a white BBC owl logo across the top.

Teletext Inserter

I have recently acquired a teletext inserter and initially managed to get it to output a default page.
Ideally if I have time I'd like to create some software to send pages to the unit so that I can create my own Teletext service.

Acoustic Modem

I've been looking for an acoustic modem for ages and they always seem to be in the USA and fetch silly prices on eBay.

Managed to get this one at a reasonable price (completely untested), so would like to wire it up the BBC and possibly dial some BBSs with it.

Already have a tone dial converted phone suitable for using with it.

Retro Challenge - 2015/07

The Problem...

I currently have a BBC Master setup on the desk in my office. The problem is that its not very portable, if I want to take it anywhere it requires a large CRT monitor or my recently acquired Gonbes VGA convertor board, a modern monitor and a set of power supplies.

You then also need to take either a disc drive or the DataCentre to give me access to disc images so that I can actually do anything.

Solution...

I have a spare BBC Master Compact which I intend to make much more portable.

To do this I intend to add the following to the machine...

1) As the original BBC Master Compact uses a large desk unit to house the disk drives I need an internal method of storing software to run on the machine.

So I bought a GoSDC board which adds an SD card allowing me to store all of the software I need to use. The device plugs into a spare ROM socket internally in the machine.

John Kortink who designed the board was kind enough to supply one without the headers as he thinks the Compact may not have enough room inside with them attached. If this is the case I will need to wire a set of switched to the board to enable and disable it for updating the firmware.

2) So that I can run the machine away from any kind of power supply I want to add an internal rechargable battery.
Probably a lithium one with a charging circuit to provide a few hours of usage without needing a power supply. Obviously when the power is supplied it should cut off and charge the battery instead.

As part of this I will add in a power switch so that the machine can be easily turned off and will allow for charging without the machine being powered up.

3) To provide a VGA output I will fit the Gonbes board internally and provide a VGA socket on the back for connecting an external monitor.

This will require the power to the board and the TTL RGB output from the BBC to be wired to the board,

4) So that I can use the machine while on battery and without a VGA monitor or TTL RGB one I intend to provide a small screen built into the machine. This will probably be a 3-5 inch screen added to the top area of the case. Depending on the screen type this will either be wired to the composite out or to the second port on the Gonbes board.

This should be a mirror of what is output to the VGA / TTL RGB. I might put a switch in to be able to turn it off as it will display even when connected to an external monitor. If I have time it would be cool if when the external monitor is connected it displayed a cool logo.