Speedy TT - English Version

General

The Speedy TT is a small PCB board, which increase the clock speed of the processor (CPU) of an Atari TT. Speedy is available in three different PCBs, depending on your type of mainboard.

Abb.1: Daughterboard Speedy Abb.2: PGA-Speedy Abb.3: SMD-Speedy

To decide, which type of Speed you need, please open your TT and have a look to your mainboard. Please remark, that the backside with connectors like monitor sub D connector, ACSI connector and so on is back, frontside is in front of you.

Overview of the three versions

Type of Mainboard	Identifying your Mainboard	Sort of Speedy
Daughterboard TT	Processor (PGA-Type) inside of an small PCB (Daughterboard) which is socket inside of the mainboard, Daughterboard is placed under the TT-RAM-Expansion-Port	Daughterboard-Speedy (short form: DB-Speedy)
PGA TT	Processor (PGA-Type) is directly socket inside of the mainboard, Processor is placed also close to the TT-RAM-Expansion-Port	Speedy for TT with PGA CPU (short form: PGA-Speedy)
SMD TT	Processor (SMD-Type) is soldered directly on your mainboard, Processor is placed under the ST-RAM-Expansions-Slot	Speedy for TT with SMD CPU (short form: SMD-Speedy)

First of all: Please be note, that the installation of Speedy needs really advanced skills of soldering! If you have a novice skill, please ask a competence person for help!

• Speedy allows you to speed up your CPU of your Atari TT up to 48 MHz.
• You can speed up your coprocessor (MC68882) of your Atari up to 48 MHz.
• If the increasing of speed doesn’t work inside of your TT, you don’t have to rework all steps! Speedy gives you the item to let them inside of your TT with normal speed.
• You could increase the access to your Alternate-RAM, if you bought the new STORM TT Rev. G. If you have an older STORM TT Revision, please make a request to your Thunderstorm Team to change the STORM TT to the newest Revision.

Technical Details

The data bus inside of all TT is depending of a 16 MHz bus speed. Atari decided short time for delivery of the first Atari-TTs to speed them up to 32 MHz. That means, that the CPU is clocked with a 32 MHz clock and the bus still driven by 16 MHz. The matching of these two clock cycles realized with two PAL/GALs (U111 and U112) and four 74F74 (U113 up to U116) inside of all TTs. In this explanation we say to this six ICs: “state machine”. The designation of these parts is in all sort of TTs the same one.

By the way: The daughterboard TT is the oldest version of mainboard. There you can see, that the TT was designed only for 16 MHz bus clock speed and 16 MHz processor clock speed. To increase the clock speed of the processor Atari made a PCB which handle this. This is the daughterboard. ☺ And the six ICs (U111 – U116) placed onto the daughterboard! The next generation of TTs is the “PGA version”. Same state machine, but now the state machine and processor are placed onto the mainboard. To reduce costs, inside the newest and latest version of TTs, Atari replace the PGA CPU at the mainboard with a SMD CPU.

Speedy replace the old state machine (remember: U111 – U116) and establish a new once, which allows us together with a PLL circuit to increase the processor speed at triple bus speed (3 x 16 MHz = 48 MHz).

To implement Speedy inside of your TT it is necessary to unsolder the old state machine. Means you have to unsold the six ICs U111 up to U116!

Another item in this case is, that the /BG (Bus Grant) signal inside of the Atari TT designed for a 16 MHz clock bus transfer. The timing match also, if the processor get an increased clock speed of 32 MHz.

Above 32 MHz this timing doesn’t matched together. The /BG signal from the CPU is to quick to recognized at the mainboard. The activation of this signal could get get lost between processor and mainboard. It’s incessant to split the /BG signal and loop it through the Speedy PCB. Speedy adapt the correct timing of the /BG signal, if the CPU is driven with 48 MHz clock speed. To split the /BG signal and to inject the new /BG signal into the mainboard is a second part, what we shall to do.

Depending of your Type of mainboard this means more or less work. If you have a daughterboard TT, it’s quite simple, because these six ICs are on the daughterboard! If you have a PGA or SMD version, it’s hard work!

Additionally, Speedy needs the both clocks (16 MHz and 32 MHz) of the mainboard. Both are easily available at the Jumper W101. W101 normally get the opportunity to switch the clock speed of the coprocessor. We use this jumper W101 to get these both clocks for Speedy. We connect all three pins of W101 to Speedy. The advantage now is, that we could offer the coprocessor 16 MHz, 32 MHz and also 48 MHz, depending which clock speed will accept from the coprocessor.

The procedure to prepare your TT is in all cases technical the same! The steps could look a bit different.

We will start the description for the SMD-TT. If you have another type of TT, please choose the chapter of your type of TT.

Open your TT and take the mainboard out of the case. Please be note of all additional part inside of your TT. Please make you some notes or pictures, which give you a good way to reassemble after all your TT in right order.

Conversion of a SMD TT

Your TT mainboard looks like the next picture. On the next picture you can see the six ICs which you have to unsolder.

Abb.4: Mainboard SMD TT with marked ICs

Depending of your Revision of mainboard, you have to remove the clock patch of the processor clock. Atari did some clock patches inside some TT’s to optimize the clock trace of the processor.

• First type is, “no clock patch”. Easy: Only removing the six ICs is necessary.
• Second type of patch is a cable connected from U110 Pin 1 to resistor (R888).
• Third type of patch is a cable connected from R997 to U210 (74AC244) Pin 17 and a second cable connected from U210 Pin 3 to resistor (R888).

Abb.5: Second type of patch Abb.6a-b: Third type of patch

In case of the both last patches you remove all cables and replace the resistor R888 (10 Ohm) onto of the marked place at the mainboard without the cables.

Next step is, to split the /BG signal coming from the CPU. We cut through the signal line onto the mainboard close to the CPU. The next picture shows a good place to divide the signal line of /BG signal.

Abb.7a-d: CPU of SMD TT with divided /BG signal

/BG signal coming from the CPU get a small cable, which shall connect to Speedy. To fall back in the old situation, it is useful to install also a female socket pin on the opposite side of /BG signal. There you have every time the opportunity to jumper the /BG signal in old situation.

Connect the /BG signal from CPU into the free female socket pin under the Speedy PCB. Additional information: The new /BG signal from Speedy goes via U112 Pin 11 into the mainboard. There is nothing to do.

Abb.8: Speedy with female socket under the PCB for injecting the /BG signal from the CPU

Be sure that all your changes matched with the next picture.

Abb.9: SMD TT Mainboard with all changes, ready to install SMD-Speedy

Abb.10a-b: SMD TT Mainboard with SMD-Speedy

After all, put Speedy on top of the sockets of U111 up to U116. Please be careful and check that all pins fit correctly into the right socket pins.

Put the small connector to all three pins of W101. The red cable is connected to Pin 1 of W101.

Conversion of a PGA TT

Your TT mainboard looks like the next picture. On the next picture you can see the six ICs which you have to unsolder.