Raspberry Pi running BASIC

Earlier on this blog, I posted something about the BASIC language on Linux. 

It turns out that all the tools mentioned in this posting are available on Raspberry Pi computers too. In fact, BWBASIC, FreeBasic and Geany work in the exact same way.

Raspberry Pi zram swap

Raspberry Pi computers may not always have the best amount of RAM available. For small embedded applications, this is just perfect, no precious ram wasted by remaining empty.
However, depending on the application, more memory might be required. The fallback would be virtual memory. In big server installations, swap is not even a topic. However, if an SD-card is were the files live on, SWAP is somewhat out of the picture.

If CPU power is not an issue, ZRAM might be a solution of the RAM-shortage of an RPi-application. 
While my RPi500 has plenty of RAM, I installed ZRAM anyways.
This is what my present memory situation looks like:

               total        used        free      shared  buff/cache   available
Mem:         8131616      835544     6173708      103560     1315828     7296072
Swap:        4270584           0     4270584

NAME       ALGORITHM DISKSIZE DATA COMPR TOTAL STREAMS MOUNTPOINT

/dev/zram0 lzo-rle       3.9G   4K   80B   12K       4 [SWAP]

NAME       TYPE      SIZE USED PRIO

/dev/zram0 partition 3.9G   0B  100

/var/swap  file      200M   0B   -2

And yes, the RPi500 is equipped with 8GB of RAM and 4 CPU cores. 

Presently I would not know how to fill up all the memory available to me.

Raspberry Pi 500 USB boot

There seems very little information on the internet on the Raspberry Pi 500. I love the RPi400, so, how could I resist to purchase an RPi500? I got the whole package, including mouse, PSU and the book.

The RPi500 comes preinstalled with a micro-SD, no surprise here. I am not a big fan of running my OS on SD-cards. So, I ordered a USB3 to SATA adapter to go with the 500. Of course my intention was to use an SSD in this setup. However, I was curious if the RPi500 could handle an spiny-disk-device. And yes, it can. Here is what I did:

Boot the RPi500 with the SD-card. Use the tool "SD Card Copier" to copy the contents of a Seagate Expansion external USB3 HDD. Surprise surprise, it worked. Once the SD-card was copied to the HDD, I shut down the RPi500 and removed the SD-card. Switching back on booted right away from the hard-drive. Of course a spiny disk does not provide a very snappy experience, but it worked. The SPi500 was able to supply the spiny disk, however, the temperature of the keyboard-computer was slightly elevated; not to an alarming level, however noticeable. 

While I call the exercise a success, I went back to the original plan and replaced the HDD with a (Kingston) SSD drive. This was done by simply using the "SD Card Copier" to copy the HDD content to the SSD.

The RPi500 runs a lot cooler and snappier now, who would have though?

Contrary to the actions one had to perform with the Raspberry Pi 4 generations, not strange commands are needed to boot the RPi5 generation using USB devices.

BASIC on Linux

Who does not remember the good old times when all (home) computers came with BASIC. To recreate the good old time feeling, BASIC had to be back on my Linux systems.

I figured out a combination of bwbasic and FreeBasic. 

The Bywater BASIC interpreter offers an interactive environment, similar to GW-BASIC. With a tiny trick, bwbasic can be used in a batch mode directly from shell. The "trick" being using the SYSTEM or QUIT statement at the end of the code, rather than the END statement. Here is an example:

10 for i=0 to 10
20 gosub 100
30 next
40 ?
50 system
100 ? i;
110 return

Line numbers are not necessary, however, line numbers allow to edit the code in the bwbasics interactive environment.

Sometimes, one might want to compile a program. In comes the FreeBasic compiler. It is important to point out that bwbasic and FreeBasic are not 100% compatible. I order successfully compile code as displayed above, one needs to the a "-lang" option. I found "fbc -lang qb [filename]" to work fine.
Another remark, while SYSTEM and QUIT are equivalents under bwbasic, fbc does understand SYSTEM, but not QUIT.

One interesting comparison is the performance of the interpreter and the compiled code.

Interpreter:
$ time bwbasic count.bas
Bywater BASIC Interpreter/Shell, version 2.20 patch level 2
Copyright (c) 1993, Ted A. Campbell
Copyright (c) 1995-1997, Jon B. Volkoff

 0 1 2 3 4 5 6 7 8 9 10

real 0m0.007s
user 0m0.003s
sys 0m0.004s

Compiled code:

$ time ./count

 0 1 2 3 4 5 6 7 8 9 10

real 0m0.038s

user 0m0.005s

sys 0m0.007s

When using the interpreter, the first 4 lines of the output are not controllable by the user of bwbasic. However, a very simple trick with the stream editor gets rid of the problem. It does not even cost a lot of extra time. This way, the output can be piped to yet another program. Have a look:

$ time bwbasic count.bas | sed 1,4d

 0 1 2 3 4 5 6 7 8 9 10

real 0m0.013s

user 0m0.005s

sys 0m0.018s

There is yet another program I want to push into the mix, Geany. This IDE integrates perfectly with the FreeBasic compiler. Just be sure to add the "-lang qb" to the Build Commands. Click Build -> Set Build Commands. The "Compile" Command would therefore look like this: fbc -lang qb -w all "%f"

Geany also supports "Run" Commands. Making use od the stream editor as above, the command looks like this: bwbasic "%f" | sed 1,4d Obviously, this run option won't function on interactive programs... just saying.

Dell Wyse 5070 Linux setup

In my previous post. I discussed the use of a Dell Wyse 5060 thing client. There is a better option, which meanwhile made it into my collection, the Dell Wyse 5070. 

The version I got is equipped with a 16GB onboard eMMC device, which is big enough for a small Linux installation. My joice fell on Xubuntu Minimal. With some additional software installed, 48% of the eMMC drive are used, roughly 6.5GB.

To keep things simple, I am using an external 2TB USB3 HDD. This disk is partitioned into a Linux swap and an ext4 partition. The ext4 partition serves as home-drive.

Swapping over USB3 is certainly not ideal. However, with only 4GB RAM, swap is desireable. In order to improve on the swap situation, zram takes care of part of the virtual memory. The total virtual memory is now 4GB (HDD) + 1.8GB (zram).