Tektronics TLA704 PCI upgrade - Page 1
Forum section: electronics / testgear

author: asp
author_rank: Regular Contributor
timestamp: July 22, 2022, 09:03:03 am
content: HiIf somebody wants to get the PCI working on a Tek TLA704 below you can find the steps to accomplish that:1. Unsolder all the pins for the PCI connector on the board and put in a PCI connector (120 pin)2. Populate R25 and R23 with a 0 Ohm resistor (5 and 3.3V) (found on the top of the board near the PCI Connector)3. Populate R4 with a 33 Ohm resistor (PCI IDSEL) (found on the top of the board near the PCI Connector)4. Populate R165 with a 33 Ohm resistor (PCICLK) (found on the bottom of the board on the opposite side of the PCMCIA connector under the crystal)This will get the PCI working BUT the BIOS will not assign any IRQs to the PCI board and when booting you will get this:Code:Warning: IRQ not configured - Pci at slot 01Bus:00, Device: 0E, Function:00System Configuration Data updatedPress <F1> to resume, <F2> to Setupregardless of the settings you do in BIOS.If somebody could take a look at the bios (maybe someone has RFDes contact info) and see it they can change/mod it to support IRQ assignment it would be awesomeThe PCI cards will be detected in Windows but it won't start. Windows will report that the device does not have an IRQ assigned to it by BIOSAttached you can find the latest bios 1.00.14For your info when I started this I wanted to add a PCI USB card so that I can add a soundcard to the device in order to play some old games on the device with sound

author: asp
author_rank: Regular Contributor
timestamp: July 25, 2022, 07:22:12 am
content: I did manage to unpack the part of the bios that deals with the whole init thing but I am kind of stuck here. I would need somebody with ASM experience in dealing with BIOSI have attached the decrypted bios part for people that want to have a look

author: Per Hansson
author_rank: Unknown
timestamp: July 28, 2022, 08:13:29 am
content: Maybe this is useless info but if you are really stuck it could maybe help:In the old days there was a project to add support for AGP cards with two IRQ devices, the extra one for the built in HDMI sound card.Many old boards did not support this and you had to edit the DSDT table in the BIOS to add that support in.In the DSDT table is also the PCI definition, so you could have a look at this and see if it is in anyway a step in the right direction:https://www.techpowerup.com/forums/threads/ati-hd-agp-card-with-hdmi-audio-problems-read-this.106690/Here is a list of boards that use the same chipset: FW82439HX (430HX "Triton II") with a 82371SB (PIIX3) south bridge:https://www.ultimateretro.net/en/motherboards/?chipsetId=276Then just start looking for a board with PCI slots that uses the Phoenix BIOS, here is one:Siemens Nixdorf System Board D969:https://www.ultimateretro.net/en/motherboards/4507Maybe you could use its DSDT table if you are able to extract it from the BIOS...P.S: Of course first double check that your board actually uses the same chipset...

author: asp
author_rank: Regular Contributor
timestamp: July 28, 2022, 02:52:12 pm
content: I did try to get the ACPI from both windows and linux and it's not there.In linux this are all the lines from dmesg that contain acpi:Code:[ 0.093403] API: Early table checksum verification disabled[ 0.097258] ACPI BIOS Error (bug): A valid RSDP was not found (20190816/tbxfroot-210)[ 0.144814] Kernel command line: BOOT IMAGE=/boot/umlinuz root=PARTUUID=feblefb9-02 rootwait console=tty0 console=ttyS0,115200n8 noinitrd acpi=force[ 1.121610] ACPI: Interpreter disabled[ 1.316789] pnp: PnP ACPI: disabledwith APM enabled in BIOS, so I don't see a way to extract the DPDT since I can't get ACPI to show upMaybe the BIOS does not implement ACPI?Also there is no /proc/acpi or /sys/firmware/acpi

author: dxl
author_rank: Regular Contributor
timestamp: July 28, 2022, 04:17:45 pm
content: TLA704's are so old that i doubt they ever had ACPI.

author: Per Hansson
author_rank: Unknown
timestamp: July 28, 2022, 04:29:11 pm
content: There is a new BIOS here that adds APM support, it requires a new LCD though, because it only works at 800x600:https://www.eevblog.com/forum/testgear/tla704-logic-analyzer-help/Not sure if it is the same BIOS as this guy made, wont hurt to ask:https://forum.tek.com/viewtopic.php?t=136518

author: asp
author_rank: Regular Contributor
timestamp: July 28, 2022, 06:53:26 pm
content: I have tested the device with the updated BIOS and it's the same thing in linux (win98 won't boot with the new bios)Below you can find a screenshoot from HWINFO for DOS running on an external monitor with the new BIOS, and as you can see it has ACPI disabled as well. It's exactly the same output for the original bios here as well as in linux regardless of the bios flavor I use.PS: I did message Jim as he is a member of the forum here but he is busy with other tasks

author: rfdes
author_rank: Regular Contributor
timestamp: February 01, 2023, 07:38:44 pm
content: Curious if this project ever completed successfully.My understanding was that the PCI connectors were not true PCI, i.e. they had some odd signals. The thought was they were used as development test connectors.

author: asp
author_rank: Regular Contributor
timestamp: February 01, 2023, 07:50:16 pm
content: With the hardware changes made to the board you will get a true PCI (it even detects the boards that you put in BUT the bios does not include code to allocate IRQ’s to the board) so basically you cannot use any pci board in it. I was thinking to get a pIRQ line from some other device and maybe it will work sharing the IRQ. For my purpose I want to add a sound card in via USBI was thinking to port an old version of coreboot but it’s too much work for something that I don’t find that rewarding

author: rfdes
author_rank: Regular Contributor
timestamp: February 01, 2023, 10:31:24 pm
content: Are we talking about the 120 pin connector that is NOT populated?I did some multimeter testing and noticed some of the pins had the wrong power supplies connected. In particular, the one of the -12V pins had +5V on it. I also seem to remember that the orientation of the connector was going to be a problem as it is configured for 5V PCI cards. Is this what you discovered?

author: asp
author_rank: Regular Contributor
timestamp: February 11, 2023, 09:07:07 pm
content: Yes. It's the unpopulated connector that is a PCI-12 and +12 are not mandatory. Actually on the boards that I have tested, the -12 and +12V pins are floating (and I do not have a board that uses either -12 or +12V at hand)If you populate all the resistors as described in the first post you will get a working PCI (not 100% compliant but working), but the issue with IRQ assignment remains valid as the bios will not assign an IRQ to the board. I have attached some images and you can see the PCI boards connected and detected by the equipment

author: nctnico
author_rank: Super Contributor
timestamp: February 11, 2023, 11:18:58 pm
content: Did you try a different PCI card? Maybe the BIOS just doesn't recognise this particular PCI card.

author: asp
author_rank: Regular Contributor
timestamp: February 12, 2023, 02:15:37 am
content: Yes! I have tried 6 different pci-to-usb cards (2 of them are in the pics in the previous post). I have also tried a PCI sound card and a Video capture card and all have the same behavior of not getting IRQs.Right now I have take down the motherboard and added a socket to it in order to upgrade de cpu to a Pentium MMX 233.So unless somebody manages to mod the bios and add IRQ assignment, nothing can be done unfortunately!

author: rfdes
author_rank: Regular Contributor
timestamp: February 14, 2023, 03:34:28 am
content: thanks for the response.Are you sure there is not another jumper that enables one of the 4 interrupts? I have heard that it is possible to directly wire the interrupt but I have no hands on experience with this and if it is even possible. Just something I read once in the past.It may also be possible to assign an interrupt from within Device Manager. If you haven't already, check the Device Manager application.

author: asp
author_rank: Regular Contributor
timestamp: February 14, 2023, 09:47:43 am
content: I have checked the board and INT[A:D]# from the PCI slot go directly to the southbridge chip to PIRQ[A:D]# pins. unfortunately the rest of the chips use direct irq adressing having their irq lines routed to irq pins on the southbridge.My best guess is that the only thing that needs fixing is some register in southbridge initialization sequence (or at least that is what I hope) (PIRQRC[A:D]). That is because by default it seems that PIRQ routing is disabledI have added a screenshot with the relevant part of the documentation

author: rfdes
author_rank: Regular Contributor
timestamp: February 18, 2023, 01:02:15 am
content: Hmmm -I might have some spare time in the next month to take a closer look at this. If so, I'll keep you in the loop.Jim