Thursday, September 8, 2016

Famciom vs. AV Famicom External - Internal Audio Mixing

There is a myth that the AV Famicom is too quiet when it mixes internal audio with external audio.  The myth goes that the external cartridge audio drowns out the internal audio from the console and gives an unbalanced and unfair impression of what the programmer intended the music and sound effects to sound like.  The conclusion is that an original Famicom, preferably an earlier model, is the ideal way to experience Famicom audio.  However, this conclusion is too simplistic and the internal/external mix is not as extreme on standard Nintendo Famicoms and AV Famicoms as one may be led to believe.

Of course Famicom audio has its own problems.  The first problem is that genuine Famicom audio is encoded into RF and decoded in a TV.  The baseline audio has a buzz and the output of the audio sounds like it was run through an oppressive low-pass filter.  The second problem is that playing a Famicom with its RF video and hardwired controllers is something of a chore.

I have made some recordings of several games which use Famicom expansion audio and internal Famicom audio.  The games in question are :

Zelda no Densetsu (Famicom Disk System, The Legend of Zelda)
Akumajou Densetsu (Konami VRC6, Castlevania III: Dracula's Curse)


Tuesday, September 6, 2016

More Keyboard Adapters : The Tandy 1000 Keyboard to Tandy 1000 TL or SL

The earlier Tandy 1000s, the 1000, 1000A, 1000 SX and 1000 TX came with a 90-key Tandy Keyboard.  The Tandy 1000 EX and HX had the 90-key Tandy Keyboard built in.  This keyboard uses its own communications protocol and timing and is not compatible with an IBM PC, XT or AT or their clones.  This keyboard uses an 8-pin DIN plug.

The later Tandy 1000s from the TL and SL onward came with 101-key keyboards.  These keyboards, called the Tandy Enhanced Keyboard, were an autoswitching keyboard that could work in an IBM PC, XT, AT or their clones.  This keyboard uses a 5-pin DIN plug and do not work in an earlier Tandy 1000.

In the technical reference manuals for the TL and SL, which are the last Tandy technical reference manuals available online, the keyboard controllers do mention Tandy 1000 Keyboard compatibility.  These computers have a 7-pin DIN connector even though an XT or AT keyboard only uses four pins.  The schematics indicate that the extra pins are used for Tandy 1000 keyboard-specific signals.


Monday, September 5, 2016

Pleasant Suprises : The Epson MGA Q205A

Sometime ago, I acquired an 8-bit ISA card called the Epson MGA Q205A.  I figured it was a CGA compatible card because it had one DE-9 female port and one RCA jack, which the standard CGA configuration.  The only unusual thing about the card was a two-position switch on the bracket plate.  The switch is labeled color/mono.  I couldn't find anything about the card in Total Hardware '99.  I noted that the card displays in color on startup instead of B&W on a color composite monitor, I figured the switch was there to turn it to B&W.  An IBM CGA displays in B&W on startup in an IBM PC or XT.



After testing the card out a bit, I was pleased that it gave composite colors reasonably close to an IBM CGA card.  I was also pleased that the card is less than 10", meaning it will fit inside a Tandy 1000 computer.  However, Trixter's CGA Compatibility Tester demonstrated that the CGA compatibility was weak when it came to the 6845 tests.  This is not particularly surprising when I determined that the card does not have a 6845 CRT Controller onboard.  Since I have three IBM CGA cards, the card rarely has surfaced in my thoughts.

Sunday, September 4, 2016

Northgate Omnikey 101 vs. IBM Model M Keyboard


I have had the privilege of being lent a Northgate Omnikey 101 keyboard.  This keyboard is identical to the layout of my IBM Model M keyboards.  I am going to first identify the features of each keyboard and then give my impressions of the Northgate compared to the Model M.


Enclosure

Model M's use PBT plastic on the top and bottom enclosures, on the key caps and the key stems.  For this reason Model M do not yellow through exposure to ultraviolet light.  On the other hand, PBT can be somewhat brittle and it is not a rare thing to see cracked keycaps on a Model M.  Because keycaps come off very easily, it is often the case that you will find a keyboard for sale with one or more missing.  The enclosure is held together with hex screws requiring a long-barreled 7/32" driver to access.  Later Model Ms, mostly made by Lexmark and Unicomp, often have drainage holes cut into the bottom half of the enclosure for liquid spills, but the IBM-made keyboards rarely have them.


Thursday, September 1, 2016

Famicom and NES Expansions and Peripherals

Famicom Peripheral List

Devices that Plug into the Famicom Cartridge Slot

Nintendo Famicom Disk System
  • 199 Official Licensed Games + Prize Cards (and unlicensed games, copying programs etc.)
  • Comes with a disk drive and a RAM Expansion.
The RAM Expansion is inserted into the cartridge slot and the cable from the RAM Expansion is connected to the rear of the disk drive.

Wednesday, August 31, 2016

The Northgate Omnikey to Tandy 1000 SX & TX Keyboard Adapter

The Tandy 1000 computers, more specifically the early Tandy 1000s, had many good features, graphics, sound, expansion, performance, integrated peripherals.  To save development costs, Tandy imported some of its designs from prior, non-IBM PC compatible computers.  The Tandy 1000 card edge printer port can be traced back to the TRS-80.  The Tandy 1000 joystick ports came straight from the Tandy Color Computer.  And finally, the Tandy 1000 keyboard is the same keyboard used in Tandy's MS-DOS (but not IBM PC) compatible Tandy 2000.

The 90-key Tandy 1000 keyboard is not exactly a pleasure to use.  Its layout is cramped and awkward, its keys are mushy and there is no tactile feedback.  Compared to the IBM PC or IBM PC AT keyboard, it feels cheap.  Typing mistakes are frequent with this keyboard.  It has some odd key omissions.  There is no Scroll Lock, and while there is a separate Home key, there is no separate End, Page Up, Page Down, +, -, or * keys.  The shift keys are too small.  While it does have F11 and F12, software made during the Tandy 1000 (except by Tandy) lifespan rarely used these keys.

Finally, the Tandy 1000 has the dreaded Hold and Print keys.  Both keys are next to important keys like Enter, Alt and Num Lock,  The Hold key acts like a true Pause key, everything is frozen until you hit the Hold key again.  People who do not know or forget how the Hold key works may think their computer has crashed.  However, the really evil key is the Print key.  Press this key twice and, unless you have a printer attached to your computer, your computer will freeze as it vainly tries to print what you are typing on the screen. Your computer will appear to freeze.  IBM avoided this issue by assigning the function to Ctrl+Print Screen.


Saturday, August 27, 2016

RetroUSB AVS vs. Analogue Nt mini - Comparison of the Enthusiast FPGA NES Clones

Until now, any kind of accurate Nintendo NES or Famicom console had to use Nintendo's CPU and/or PPU chips, whether that console was manufactured by Nintendo, Sharp or anyone else.  While the idea of implementing a NES on an FPGA was an idea with a long history, only this year are products finally making it to market.  Here I am going to compare the features of the two announced FPGA NES implementations, the RetroUSB AVS and the Analogue Interactive Nt mini.

Console AVS Nt mini
Producer RetroUSB Analogue, LLC
Hardware Designer Brian Parker “bunnyboy” Kevin Horton “kevtris”
FPGA Type Xilnix Spartan 6 XC6SLX9 Altera Cyclone V
Included HDMI, USB Cable (mini-to-standard), Power Supply HDMI, USB, 8Bitdo NES 30 Wireless Controller, Retro Receiver, Power Supply
Outputs HDMI, USB HDMI, Analog Video, RCA Stereo
Inputs 4 x NES Controller Ports, 1 x Famicom Expansion Port 4 x NES Controller Ports, 1 x Famicom Expansion Port, Microphone Input
Upgrade USB Port SD Card Slot
Resolution Support 720p 480p, 720p, 1080p (HDMI)
240p (analog sources only)
Video Display Support HDMI Composite, S-Video, Component, RGB, HDMI
Buttons Separate Power & Reset Combined Power & Reset
Unique Special Features NA Scoreboard, Built-in Game Genie, Turbo-in-Software Scalers, Famicom Expansion Audio Generation, Audio Visualizer, Famicom Microphone, NES Zapper/Famicom Gun Support (Analog video only), R.O.B/Family Robot Support (Analog video only)
Price $185.00 $449.00
Availability September, 2016 January, 2017

Sunday, August 21, 2016

Boulder Dash - PC Speed and Joysticks

Boulder Dash was originally released for the IBM PC and PCjr. in 1984 by First Star Software.  The disk included two separate executables, one for the IBM PC and one for the IBM PCjr.  The disk was a PC booter.

The IBM PC executable is serviceable but not particularly impressive.  There is a distinct lack of animation on the title screen and for the amoeba tiles.  There is also no color-cycling effect for the diamonds.   It is debatable whether the game really uses composite color graphics.  Sound effects are weak even by PC speaker standards.

The IBM PCjr executable, on the other hand, is much, much more impressive.  It uses the 3-voice PCjr. chip for music and sound effects.  It supports 16-color graphics with full animation and color cycling.  Despite the PCjr. being slower than the PC, it does not suffer from a lot of slowdown, despite the extra effort.  Compare these pairs of screenshots from the PC and PCjr. executables :