Synchr030

Synchr030 User's Manual
Firmware v0.8.0

1. Overview

Synchr030/S is a PDS SDRAM accelerator card for the Macintosh SE/30, equipped with 256MB of SDRAM coupled to a custom controller. An extension enables fast, 2-cycle reads and writes, doubling memory bandwidth over SIMMs. Performance is equal to an L2 SRAM cache that never misses. To further boost performance, ROM is shadowed to SDRAM, where it can execute faster.

A IIsi-derived ROM such as the Rominator II is highly recommended. It is required to enable the full 256MB of SDRAM in System 7. Also, the Rominator II does not test RAM at startup, which is a lengthy process with large amounts of RAM present. 2. Features

Increases the performance of a stock or accelerated 68030.
Fastest possible 2-cycle reads and writes - 2X SIMM bandwidth.
Eliminates the need for DRAM SIMMs and slots.
Fixed access times - no stalling for refresh cycles
Improves overall performance and responsiveness (+25% MacBench 3 CPU score, +70% memory bandwidth in APD).
32-bit data path
256MB usable in System 7 with Rominator II and extension.
ROM shadowing increases Toolbox routine performance by relocating to SDRAM
Low power consumption, comparable to SIMMs
Works with Connectix Maxima to enable large, persistent Ramdisks.
FPU activity LED indicator
PDS pass-through connector
Jumper-selectable /STERM or /DSACK signaling
Works with Interware Booster accelerator
Works with PowerCache P33 accelerator
Expansion connection for additional devices.
In-system firmware updates.

3. Specifications

Power consumption: 2.15W (0.43A @ 5V)
SDRAM capacity: 256MB
SDRAM frequency: 63MHz
Maximum transfer speed: 31.33MB/s read and write
Weight: 123g
Interface: SE/30 PDS male, passthrough female

4. Installation

Remove the logic board from the computer.
Remove all DRAM SIMMs from the logic board. SIMMs cannot be used while Synchr030/S is installed.
Solder the /ECS tap to the logic board. This significantly increases performance with the stock 15.66MHz CPU. Installing it is highly recommended, but Synchr030/S will function without it. It provides no benefit with accelerated CPUs.
1. Pass the wire on the /ECS tap through a hole in the logic board near the ADB IC, from the bottom side.
2. Position the /ECS tap over the CPU pins so that all of its through holes are occupied by CPU pins.
3. Two pads on the tap should be soldered: GND and /ECS. These are labeled on the silkscreen.
Reinstall the logic board and its connections.
Verify the proper /DSACK or /STERM jumper setting is selected. Choose /STERM if a CPU accelerator is not present.
Plug the Synchr030/S card into the logic board.
Attach the wire from the /ECS tap to the 1-pin /ECS header on the Synchr030/S.
Turn the computer on and verify it can boot to desktop.
Copy the Synchr030/S Extension to your Extensions folder.
Restart the computer and verify the "ACCEL" LED illuminates.

5. Indicators

Synchr030/S PCB has four LED indicators. The amber PWR LED on the top side of the PCB illuminates while the SE/30 is powered on. The remaining three LEDs are on the bottom side of the PCB. These are visible through the frame of the SE/30 and through a MacEffects clear case:

ACCEL LED (emerald) - This LED indicates fast access to SDRAM. It illuminates once the Synchr030/S Extension is loaded.
/ECS LED (white) - Indicates activity on the /ECS signal from the 030 on the logic board. When a CPU accelerator is installed, this LED will be off, even while an /ECS input is connected.
FPU LED (yellow) - Indicates CPU access to the floating point unit (FPU).

ACCEL LED	/ECS LED	Read	Write
On	On	2-cycle	2-cycle
On	Off	3-cycle	2-cycle
Off	On/Off	4-cycle	4-cycle

6. Extension

ROM Shadowing:

The SE/30 ROM contains a collection of frequently accessed routines, typically for drawing and other common operations. A read access to the ROM takes four CPU cycles. Because accessing SDRAM takes only two cycles, shadowing (copying) the ROM code to SDRAM and executing it from there, yields a significant improvement in performance. Shadowing may be disabled by holding the 'H' key as the extension loads at startup.

When shadowing is enabled, the extension will display an "S" with a shadow as it loads.

When shadowing is disabled, the extension will display an "S" without a shadow behind it.

Notes for CPU Accelerators:

Some ROM routines, such as audio and floppy functions, depend on precise CPU timing. When faster CPUs execute these routines, they don't run correctly. Accelerators employ various methods of slowing down access to certain areas of ROM in order to maintain functionality. When these routines are shadowed to SDRAM, the accelerators' throttling measures are no longer effective. If Synchr030/S's shadowing feature causes audio, floppy or other issues with your accelerator, shadowing may be disabled by holding the 'H' key during startup, when the extension loads. When shadowing is disabled, the "S" in the extension icon will appear without a shadow behind it.

System heap expansion:

The Synchr030/S extension will allocate an additional 256KB to the System heap. This reduces the prevalence of out of memory errors when plenty of free physical RAM is available. 7. Boot Process

32-bit with extension and Rominator II:

The Rominator II reports 128MB of RAM.
The extension is loaded and soft-reboots the computer.
On the second boot, the Rominator II reports 256MB of RAM.
The extension is loaded again. If the 'H' key is held at this point, ROM shadowing is disabled.
Other extensions are loaded.
The Finder is loaded and enters the desktop.

24-bit with extension:

The Synchr030/S extension is loaded. If the 'H' key is held at this point, ROM shadowing is disabled.
Other extensions are loaded.
The Finder is loaded and enters the desktop.

Without extension:

Without the extension loaded, performance is identical to 128MB of DRAM SIMMs.

8. Known Issues

Apple Personal Diagnostics:

The long and short memory tests will hang at about 97%. APD disables the MMU temporarily and attempts to access memory directly. This results in memory corruption which causes the computer to freeze.